Hot roast beef sandwiches with onion jam might just be the tastiest sandwich we’ve ever eaten!  Layers of shaved roast beef are piled on top of garlic rolls and topped with melted mozzarella and a homemade sticky-sweet onion jam to seal the deal.  

Hands holding roast beef sandwich with onion jam.


We love a good roast beef sandwich, and this one is the king of all roast beef sandwiches.

There’s something so good about the combination of ultra-thin shaved roast beef on top of garlic bread with melted mozzarella

But the onion jam used for this roast beef sandwich recipe just takes it over the top!

These hot roast beef sandwiches are perfect for game day/Superbowl gatherings alongside Buffalo wings, spinach artichoke dip, and garlic steak bites.

Ingredients shown: 4 hard rolls, roast beef, mozzarella, onions, balsamic vinegar, and sugar.

How to make it

Each number corresponds to the numbered written steps below.

Note: The garlic bread (step 3) can be made at the same time as the onion jam.  This will save you time.

  1. Dice 3 large sweet onions and saute them in 1/4 cup of olive oil until golden (about 12-15 minutes) (Photo #1).
  2. Add 3/4 cup of sugar, 1 cup of balsamic vinegar, and a 1/2 teaspoon of dried thyme, and cook for another 10 minutes or until the jam has thickened.  Note:  I added a sprig of rosemary here because I didn’t have thyme, but you could use either one or none depending on your taste (Photo #2).
Roast beef sandwich with onion jam recipe process shot collage group number one.
  1. Preheat the oven to 350f and set the first rack in the middle and the other rack to the top 1/3 of the oven. Grate 5 cloves of garlic and mince 1/4 cup of flat-leaf Italian parsley.  Add 1/4 cup of olive oil and 8 tablespoons of unsalted butter to a pan and saute the garlic over medium-low heat for 2-3 minutes or until fragrant.  Turn off the heat and add 1/4 teaspoon of crushed red pepper flakes, if using, and parsley along with a pinch of salt, to taste (Photo #3).
  2. Slice 4 large kaiser rolls in half and place them on baking sheets lined with foil.  Distribute the garlic butter and 3 tablespoons of grated Pecorino Romano cheese all over the insides of each roll.  Cover the rolls with foil (Photo #4).
  3. Bake the rolls for 12 minutes on the lower rack, then remove the foil and move the bread to the higher rack.  Broil for 1-3 minutes or until the bread is golden around the sides and sizzling but not burnt.  Keep a close eye on the rolls while in the broiler to prevent burning (Photo #5).
  4. By now the jam should be thick and you can taste test and make any adjustments to salt, pepper, or sugar levels (Photo #6).  
Recipe process shot collage group number two.
  1. Begin to distribute 1 pound (~1/4 pound roast beef per sandwich) of shaved or thinly sliced roast beef on the bottom part of the 4 garlic bread rolls, then top with 2-3 slices of mozzarella cheese and broil until the cheese melts (about 2-3 minutes).  Again, watch carefully to prevent burning (Photo #7)
  2. Spread the onion jam on the top half of the sandwiches, then place the top rolls onto the bottom to create the hot roast beef on garlic bread sandwiches (Photo #8).  Enjoy!
Hands holding cut in half roast beef sandwich.

Top tips

  • The roast beef.  When you get to the deli counter, request that the roast beef be “shaved”, rather than thin sliced.  Shaved roast beef will give you the best texture for this particular sandwich, but in reality, almost all sandwiches benefit from having the meats thinly sliced.
  • Onion jam.  The onion jam we’ve made here is so easy and so good and we strongly recommend making it!  It is moderately sweet so if you’re looking for something a little less sweet, use less than the 3/4 cup of sugar we have in the recipe to start.  You can always add a little more at the end if need be. Pictured above is the jam made with a sprig of rosemary but in the past, I’ve made the jam with a sprig of fresh thyme, or dried thyme as outlined in the recipe card.  When I shot these recipe photos we did not have thyme on hand so I used rosemary.  Both are great and are up to you if you want to use one or the other, or neither!
  • The garlic bread.  We used New York deli-style rolls with poppy seeds but if you live in other areas without access to these rolls, look for kaiser or other types of hard round rolls.  You could also use hero or sub rolls to make a larger more substantial sandwich. If you’d like to make a full loaf of Italian bread to make these sandwiches, follow our garlic bread recipe.  The process to turn the rolls into garlic bread is simple and we do strongly recommend using fresh garlic instead of jarred garlic.
  • Toppings.  There are many possibilities for hot roast beef sandwich toppings.  We’ve chosen to use deli sliced mozzarella cheese and of course the onion jam!  These sandwiches would also be great topped with bacon, blue cheese/gorgonzola, crispy fried onions or shallots, homemade giardiniera, or creamy horseradish sauce.  Be creative and most importantly, top with what you like!
Closeup shot of roast beef sandwich with onion jam on cutting board.

More great sandwich recipes

If you love sandwiches as much as we do, here are a few of our most loved sandwich recipes!

  • Italian hero – This is the classic hero layered with Italian cold cuts, provolone cheese, lettuce, tomato, onion, and oil and vinegar.
  • Pepper and egg sandwich – Eggs, peppers, and if you want, mozzarella cheese on hard round rolls.
  • Bacon egg and cheese sandwich – New York deli-style breakfast sandwich that’s as authentic as it gets.

If you’ve enjoyed this hot roast beef sandwich recipe or any recipe on this site, give it a 5-star rating and leave a review.

We strive to satisfy a number of learning styles.  If you are someone who prefers to learn by watching, you can find most of our recipes on YouTube and our Facebook Page.

Hot Roast Beef Sandwiches with Onion Jam

4.92 from 12 votes
Prep: 5 minutes
Cook: 30 minutes
Total: 35 minutes
Servings: 4 sandwiches
Hot roast beef sandwiches with layers of shaved roast beef on garlic rolls topped with melted mozzarella and a homemade onion jam.

Ingredients 

For the garlic rolls

  • 8 tablespoons unsalted butter
  • 1/4 cup olive oil
  • 5 cloves garlic grated
  • 1/4 teaspoon crushed red pepper flakes optional
  • 1/4 cup flat-leaf Italian parsley minced
  • salt to taste
  • 4 large hard rolls
  • 3 tablespoons Pecorino Romano grated

For the onion jam

  • 1/4 cup olive oil
  • 3 large sweet onions diced, about 2 pounds
  • 1/2 teaspon kosher salt
  • 3/4 cup sugar
  • 1 cup balsamic vinegar
  • 1/2 teaspoon dried thyme

For the sandwiches

  • 4 large garlic rolls from above
  • 1 pound roast beef sliced thin or shredded
  • 1/2 pound mozzarella cheese sliced
  • 1 cup onion jam from above

Instructions 

For the garlic rolls

  • Preheat oven to 350f and set the first rack in the middle and the other rack to the top 1/3 of the oven.
  • Saute the garlic in the butter and oil for 2-3 minutes over medium-low heat or until fragrant. Turn off the heat and add in the crushed red pepper flakes and parsley along with a pinch of salt (to taste).
  • Cut the rolls open and distribute the garlic butter all over the inside of each roll. Sprinkle with the Pecorino then place the rolls on a baking sheet and cover with foil.
  • Bake for 12 minutes on the lower rack then remove the foil and move the bread to the higher rack. Broil for 1-3 minutes or until the bread is golden around the sides and sizzling but not burnt. Watch the whole time and be prepared to remove it quickly.

For the onion jam

  • Saute the onions in olive oil over medium heat until golden (about 15 minutes).
  • Add the salt, sugar, balsamic vinegar, and thyme. Cook for another 10 minutes or until the jam has thickened.
  • Taste test and adjust salt, pepper, and sugar levels to taste. Pour the jam into a bowl and set aside.

For the sandwiches

  • Place the roast beef then top with mozzarella on the bottom half of each roll, dividing evenly. Place just the bottom sides onto a baking sheet and broil until the cheese melts (about 2-3 minutes). Watch carefully!
  • Spread the onion jam on top of the sandwiches then place the top rolls onto the sandwich. Enjoy!

Notes

  • 3/4 cup of sugar will yield a moderately sweet onion jam. Feel free to use more or less sugar to taste. 
  • Leftovers can be saved in the fridge for up to 3 days and can be reheated in the oven wrapped in foil at 350f until warm.

Nutrition

Calories: 1117kcal | Carbohydrates: 82.4g | Protein: 56.7g | Fat: 63.7g | Saturated Fat: 27g | Cholesterol: 199mg | Sodium: 624mg | Potassium: 733mg | Fiber: 3.7g | Sugar: 44.6g | Calcium: 535mg | Iron: 24mg

Nutrition information is automatically calculated, so should only be used as an approximation.

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26 Comments

  1. Deborah Negron says:

    5 stars
    This is so great using deli roast beef for a quick(er) sandwich. Do you have a recipe for a good slow cooking in the oven roast beef?

    1. Tara says:

      Hi Deborah, thanks for the comment. Jim has a recipe for prime rib, but no recipe for roast beef at the moment. At some point he will.

  2. Linda says:

    5 stars
    Yes indeed, I made the onion jam and it is one of the best things I have ever eaten. I didn’t have Balsamic vinegar so I substituted apple cider vinegar and it still turned out super yummy. I am a vegetarian so I didn’t make the roast beef. But I smeared the onion jam on a toasted baguette with a chunk of good sharp cheddar and it was wonderful! Thank you for posting the recipe Jim!

    1. Jim says:

      Hi Linda, I’m so happy you enjoyed the onion jam – I can imagine how good it was on a toasted baguette with sharp cheddar!

  3. Laura says:

    5 stars
    These were absolutely delicious! Super easy for a weeknight meal and everyone loved them! The only things I changed were I cut back on the sugar in the onions and used brown sugar instead and I also added horseradish on the roll after everything was done! Definitely will make these again

    1. Jim says:

      Hi Laura, thanks for the comment and so happy you enjoyed these. Horseradish is a great addition here – thanks for sharing!

  4. Den M. says:

    Jim, your recipes are not always delish but also fun, down to earth in the best way. So glad we have found your site.
    Have you eaten these sandwiches at room temp? I would like to make for a group, it is likely they will not be warm by the time they are eaten. I am wondering if it makes sense to make the sandwich but not melt the cheese, just eat as a regular sandwich. Or, go ahead and melt the cheese even though they will sit before serving. So, is the melted cheese still good tasting once room temp or is never melted cheese the way to go. What are your thoughts on this? Thank you.

    1. Jim says:

      Hi Den, thanks for the comment and so happy you’re enjoying the recipes! The sandwich will be good either way, but I’d recommend melting the cheese ahead of time and serving at room temperature. Hope you enjoy!

  5. Kristi says:

    Hi. Curious about this, I’m actually currently making the onion jam. It seems to still taste very strongly of vinegar, even after simmering for 15 minutes. I’ve added a bit more sugar, but I don’t want it to be overly sweet, either.

    1. Jim says:

      Hi Kristi, you can let it cook a little longer if it’s too vinegary for you. All vinegars are different so it could just be the vinegar you used is more acidic.

  6. Ileen Cuccaro says:

    5 stars
    Have already made quite a few of your recipes started with the pizza and on from there, they are all 5 stars. My mouth was drooling over this one

    1. Jim says:

      Hi Ileen, thanks for the comment and so happy you’re enjoying the recipes!

  7. Lorraine Baum says:

    5 stars
    Can’t wait to make this sandwich! It looks so good. Thank you for all you do, life is better because of sipandfeast.

    1. Jim says:

      Hi Lorraine, thanks for the kind words and hope you enjoy the sandwich!

  8. Elizabeth Anne Schiller says:

    5 stars
    Omg! This is absolutely delicious! What a great sandwich! Thanks for the onion jam. Great condiment that I will use all the time now. Thank you so much!

    1. Jim says:

      Hi Elizabeth, thanks for the comment and review and so happy you enjoyed the sandwich!

  9. Bob Pagano says:

    5 stars
    This looks amazing. Must try!

    I would be interested in your take on The Bombette.

    1. Jim says:

      Hi Bob, thanks for the comment! I’ve never heard of it but just read about it and it sounds great.

    2. Lisa Bilak says:

      Made this tonight for dinner I followed the recipe exactly and it was absolutely delicious. The onion jam is a game changer I could probably eat it on everything. Thanks for sharing!

      1. Jim says:

        Hi Lisa, I’m so happy you enjoyed the recipe, and agree the onion jam can go on everything! Thanks for the comment!

  10. Purvi Rajani says:

    This looks amazing. How long can the onion jam be stored in the fridge?

    1. Jim says:

      Thanks, Purvi. The onion jam will be good for 3 days in the refrigerator, maybe a little longer.