Preheat oven to 350° F. Spray a 9-inch pie pan or 8x8 casserole dish with cooking spray.

Heat the oil in a large skillet over medium-high heat until shimmery. Saute the onion until translucent, about 3-4 minutes. Stir in the garlic during the last 30 seconds. Add the ground beef and saute until browned, breaking it up with a wooden spoon, about 4-5 minutes. Drain off the grease, if desired.

Stir in the drained tomatoes & chilis, and enchilada sauce. Stir mixture thoroughly, reduce heat to low, and let simmer for about 10 minutes.

While meat mixture simmers, warm up the refried beans in a microwave-safe bowl in 30-second increments or in a pot on the stove over low heat, stirring until softened. Spread a thin layer of refried beans (a generous 1/4 cup) on one side of each tortilla. Set aside. (Note: If using corn tortillas, cut 3 of them in half. Then use 1 1/2 corn tortillas per layer in the next step.)

In the bottom of the dish, spread 1/3 cup of the meat mixture. Cover with a tortilla (bean-side up), followed by 1/3 cup meat mixture, and then 1/4 cup shredded cheese, spreading the ingredients out evenly. Repeat tortilla/beans, meat, and cheese pattern until all the tortillas are used up, ending with the cheese on top. 

Bake for 25 to 30 minutes (perhaps longer if using a ceramic dish), or until cheese is melted and it's hot throughout. Serve slices warm with your favorite Mexican toppings, like sour cream, salsa, guacamole, or diced avocado, sliced green onion, etc.