Ground beef, pinto beans, and tomatoes spiced with chili powder bubble under a crunchy, gooey topping of tortilla chips and two cheeses in this quick and easy, kid-friendly casserole.
Preheat oven to 425 degrees. Heat a 10-inch cast iron skillet over medium-high heat. Add ground beef; season with salt and pepper. Cook, stirring frequently with a wooden spoon to break up meat, until meat is browned, 10 minutes. Transfer beef to a colander to drain. Discard excess oil.
Wipe out skillet, add oil, and return to heat. Add bell pepper and onion. Cook, stirring, until tender and browning, 7 minutes. Add tomato paste; cook, stirring, 1 minute. Add back reserved beef, chili powder, oregano and cumin, tomatoes (with liquid), pinto beans, and 2 tablespoons water; bring to a boil. Remove from heat. Season with salt and pepper.
In a large bowl, combine tortilla chips, 1 cup Monterey jack, and 1 cup cheddar cheese. Top casserole with chip mixture followed by remaining 1/4 cup each of Monterey and cheddar cheese. Bake until cheese is melted and golden in spots, about 3 minutes. Serve with radish, jalapeno, olives, sour cream, and cilantro.