Lay 1 tortilla on a flat work surface and sprinkle with 1/4 cup shredded cheese. Spoon 1/2 chicken and vegetable mixture on top of cheese, then top with an additional 1/4 cup cheese. Top with another flour tortilla. Heat a large nonstick skillet with cooking spray over medium heat. Carefully place 1 quesadilla in pan and cook 3 minutes. Using a large spatula, gently flip quesadilla and cook an additional 3 minutes until lightly browned and cheese is melted. Repeat with second quesadilla. Slice each quesadilla into quarters. Place 2 quarters on a plate with 1 tablespoon sour cream and 2 tablespoons salsa.