Heat a pan on medium heat. Add olive oil and onions. Cook until translucent.
Add minced garlic. Cook 30 seconds longer.
Add black beans, salsa and all the spices. Cook until salsa cooks down, about 8-10 minutes. While it's cooking, mash about half the beans into the salsa mixture.
Add corn and cook until heated through, about 2-3 minutes.
Warm taco shells according to instructions on pack. Pile bean and corn mixture into taco shells. Add salsa, shredded lettuce, and tomatoes.