Add the 1 Tablespoon of vegetable oil to a skillet.
Finely dice the onion.
Saute the onion until soft.
Measure 15 oz of beans.
Chop up 1 green bell pepper.
Add in pepper and beans.
Add onion, pepper, and bean mixture to the tortillas.
Shred the cheddar cheese.
Add the shredded cheese to the tortilla.
Add 1/4 cup of vegetable oil to two skillets.
Add the quesadillas to the two skillets and cook.
Cut the quesadillas into 8 pieces.
Cut up avocado and place on quesadilla if wanted.