Heat oven to 450 degrees.
Cut potatoes into ⅜-1/2 inch strips.
Oil potatoes on both sides in roasting pan with 4 Tbsp of olive oil. Make sure the potatoes are well oiled to avoid sticking. Use wire rack if you have one.
When oven reaches 450 degrees add potatoes and cook for 30 minutes.
While potatoes are cooking whisk miso paste, sugar, mirin, soy sauce, and sesame oil in bowl.
Chop green onions on a diagonal and reserve for later.
Remove potatoes from oven and turn on broiler.
Brush paste mixture onto potatoes liberally. You can use all the paste if desired. Return potatoes to broiler for 3 minutes.
Remove potatoes from broiler and garnish with green onions and sesame seeds. Enjoy!