In a large skillet over medium-high heat, cook ground beef, onion, and garlic until beef is browned and vegetables are soft, about 5 minutes.
Drain fat from the skillet, then stir in chili, chili powder, cumin, oregano, salt, black pepper, and red pepper flakes. Cook for an additional 5 minutes.
In a 9x13-inch baking dish, layer Fritos, ground beef mixture, cheese, tomatoes, and jalapenos and olives (if using).
Bake for 20 minutes, or until cheese is melted and bubbly.
Serve hot.
Interesting Facts
Frito Pie originated in Texas in the 1940s and is a favorite amongst Texans.
Frito Pie is traditionally served in the Fritos bag, but it can also be served in a traditional pie dish.
This dish is a great way to use up leftover chili.