Preheat the oven to 350° and lightly grease a 9×13 casserole dish. (This casserole can actually be cooked right in the 12-inch skillet that you use to cook beef and vegetables or in a separate 9×13 casserole dish.)
Slice onions and bell peppers and saute until softened. Add tomatoes and garlic and saute until garlic is fragrant.
Take vegetables out of the pan, and set aside. Saute ground beef in the same pan as the vegetables, breaking up all the clumps until beef is browned.
Mix cooked vegetables back into the beef.
Add spices, diced chili in adobo sauce, tomato sauce, salt, and sugar. Mix well, pour in hot beef stock, and add rice. Stir everything until evenly incorporated. You can cook beef and rice mixture right in the skillet or transfer it into a casserole dish at this point.
Cover the skillet tightly (or the casserole dish) with a sheet of aluminum foil and bake for about 40 minutes. (Note: if using different rice, bake time could be a few minutes more or less.)
Take the skillet out of the oven and take off the foil. Sprinkle cheese evenly over the top of the casserole and bake for another 5-7 minutes.