4-Ingredient Healthy Chicken Quesadilla Casserole

diced (cooked chicken (such as rotisserie chicken or leftovers from another meal))

taco sauce or salsa

2% shredded cheddar cheese

whole wheat tortillas (I used LaTortilla Factory Low Carb Whole Wheat Tortillas)

Optional garnish: fresh cilantro (sliced green onions, sliced olives, sliced tomatoes, diced avocado)