Preheat oven to 375 degrees, and spray a 9x13 inch baking dish with cooking spray. Set aside. Start cooking rice according to package using the broth as the liquid.
In large saute pan, heat olive oil over medium heat. Cook onion, and red pepper in olive oil. Add a little salt and pepper and cook about 5-7 minutes. Add garlic and cook about 1 minute. Add both cans of beans, garlic powder, onion powder, and about 1/2 - 3/4 cup of stock. Stir over medium heat and reduce until thick and beans are mushy. Add more stock as necessary (about 20 minutes). Add salt and pepper to taste.
Start to layer in baking dish. Lay tortillas just enough to cover the bottom, 1 cup of cheese, half of the rice, all the spinach, all the bean mixture, other half of rice, another layer of tortillas, then topped with remaining cheese.
Bake about 20-30 min until cheese is bubbly and crispy.
After baking, garnish with sliced avocado and chopped cilantro. Serve with, salsa, sourcream, and maybe a splash of lime.