1 tablespoon vegetable oil
1 white onion, diced
1 (10.75 ounce) can condensed cream of mushroom soup
1 (10.75 ounce) can condensed cream of chicken soup
1 (10 ounce) can diced tomatoes with green chile peppers (such as Rotel))
1 cup chicken broth
2 tablespoons sour cream
2 teaspoons ground cumin
1 teaspoon chile powder
1 cooked chicken, torn into shreds or cut into chunks
8 ounces shredded Cheddar cheese
10 flour tortillas
Preheat oven to 350 degrees.
Heat oil in a large skillet over high heat.
Saute onion until warmed through and somewhat soft.
Combine onion, cream of mushroom soup, cream of chicken soup, diced tomatoes, chicken broth, sour cream, cumin and chile powder together in a large bowl and stir until sauce is well-combined.
Spread a few tablespoons of the sauce in the bottom of a 9x13-inch baking dish.
Spread 1/2 the chicken over the sauce.
Spread about half the sauce over the chicken and top with 1/3 the cheese.
Spread a layer of tortillas over the cheese.
Spread remaining 1/2 the chicken over the tortillas, and top with almost all of the remaining sauce, reserving 1/2 cup sauce.
Top with 1/3 the cheese, remaining tortillas, the reserved 1/2 cup sauce, and remaining 1/3 cheese.
Bake casserole in the preheated oven until bubbling, about 40 minutes.
Increase the oven temperature to broil.
Broil the casserole until top is golden, 2 to 3 minutes more.
Remove and let sit for about 5 minutes and then cut and serve!