- Heat 1 tablespoon olive oil in 12" nonstick skillet over medium-high heat.
- Cook onion, pepper and zucchini, stirring occasionally, 4 minutes or until tender.
- Reduce heat to medium and stir in 1-1/2 cups sauce, simmer, stirring occasionally, 5 minutes or until sauce is thickened.
- Evenly spread sauce mixture on tortillas, leaving a 1" border. Sprinkle evenly with cheese and fold in half; set aside. Clean skillet.
- Heat remaining 1 tablespoon olive oil in same skillet over medium heat and cook quesadillas, two at a time, turning once, 4 minutes or until golden brown and cheese is melted.
- Cut quesadillas into wedges and serve with remaining sauce, heated.
Quesadillas can also be baked. Place folded filled tortillas on baking sheet and bake in preheated 425°F oven for 5 minutes or until cheese is melted. Cut and serve as above.