Preheat oven to 400° F
Season chicken with salt and pepper
Add the chicken and water to a small skilled and cook on medium-high heat. Bring to a simmer and cover.
Reduce heat to medium-low and cook approximately 10 minutes or until chicken is fully done. Turn over once mid-way through cooking.
Remove skillet from heat and let chicken cool. Once chicken is cooled, dice or shred into small pieces.
Cover the bottom of a 7x11 baking dish with 1/3 of tomato sauce. Arrange 3 tortillas on top of sauce (they will slightly overlap). Sprinkle 1/3 of chicken and cilantro over tortillas. Top with 1/3 of cheese
Repeat the layers of sauce, tortillas, chicken and cheese 2 more times.
Top the final layer with the fresh, diced tomato.
Cover with foil and bake until bubbly (about 20 minutes).
Remove foil and cook 10 more minutes or until top is lightly browned.