Make sure shrimp are completely defrosted before marinating (if using frozen shrimp).
Chop garlic coarsely and chop fresh cilantro.
Combine half of the garlic, shrimp, tequila, juice of 2 limes, salt, pepper, baking soda, cumin, and paprika in bowl and mix thoroughly. Cover and refrigerate for 15 mins, but no longer than 1 hour.
After 15 mins remove shrimp and drain.
Heat cast iron or heavy skillet to medium heat. Add other half of chopped garlic and saute for 2-3 minutes.
Add shrimp and saute about 3 minutes per side. The shrimp will be nice and plump with a pink color when fully cooked.
Before turning off heat squeeze juice of 1 lime onto shrimp. Add the cilantro at the very end.
Plate and serve with tortillas, marinated onions, sour cream and any other sides you desire. Enjoy!