Chili Beef Casserole

Preheat oven to 350 degrees F (175 degrees C). Lightly grease a medium casserole dish. In a skillet over medium heat, cook the ground beef until evenly brown. Drain, and set aside. Heat the olive oil in a separate skillet over medium heat, and cook the onions until tender. Mix in the green pepper and peas, and season with chili powder and red pepper flakes. Stir the cooked beef, tomatoes, and tomato paste into the mixture. Reduce heat to low, and simmer 5 minutes. Mix in the kidney beans and corn. Spoon 1/2 the skillet mixture into the prepared casserole dish, and top with 1/2 the tortilla quarters. Layer with remaining skillet mixture. Cover and bake 25 minutes in the preheated oven. Remove cover, and top with remaining tortillas and cheese. Continue baking 10 minutes, or until cheese is melted and golden brown.