Preheat oven to 425°.Heat olive oil over medium heat. Add bell peppers and onion and cook until soft, about 5 minutes. Remove from skillet and set aside. Add ground beef to skillet and cook, breaking up meat with a wooden spoon, until beef is no longer pink, about 5 minutes. Drain fat, then stir in cumin, chili powder, paprika and season with salt and pepper.