In a mixing bowl, combine sour cream, salsa verde and milk and stir until combined.

In a 9x13 casserole dish, spread a small amount of the sour cream mixture to cover the bottom of the dish.

Cut the tortillas in half and layer 6 half pieces (3 whole tortillas) with the flat (cut side) against the edges of the pan to cover the bottom.

Spread half of the chicken over the tortillas, then half of the avocado on top of the chicken.

Spoon half of the remaining sauce mixture over the chicken and avocado and then cover with half the cheese.

Repeat with the remaining ingredients- tortillas, chicken, avocado, sauce, cheese.

Bake at 350? F for 40-50 minutes or until it is heated through and the cheese is melted and bubbly.

After removing from the oven, let rest for 5-10 minutes and then cut and serve.

Garnish with cilantro and tomatoes if desired.

Enjoy!