Vegetarian Quesadillas

Spray a nonstick skillet with cooking spray. Add zucchini, squash, and onion; cook, stirring occasionally, for 5 minutes. Add garlic. Continue cooking until vegetables are tender, about 2 minutes more.

Spread a scant 1/4 cup refried beans over each tortilla. Set 4 tortillas aside to be the tops of the quesadillas. Spoon 1/4 of the vegetable mixture over the remaining 4 tortillas. Sprinkle 2 tablespoons Cheddar cheese over the vegetables. Cover with the reserved tortillas, bean-side down.

Wipe skillet out with a paper towel. Heat oil in the skillet over low heat. Add 1 quesadilla. Cook until browned and heated through, 2 to 3 minutes per side. Repeat with remaining quesadillas. Serve each quesadilla with 1/4 cup salsa.