Taco Cups

Preheat oven to 350°. Grease muffin pan with cooking spray. Stamp out tortillas with a 4" biscuit cutter. Place a tortilla into each cup of muffin pan, folding the edges if necessary. Set aside. In a large skillet over medium heat, heat olive oil. Add onion and cook until softened, about 5 minutes. Add ground beef, breaking up the meat with a wooden spoon. Season with taco seasoning, salt, and pepper and cook until the meat is no longer pink, about 6 minutes. Drain fat. Spoon cooked beef mixture into each tortillas, then top with shredded cheddar. Bake until the tortillas are golden around the edges and the cheese has melted, about 10 minutes. Garnish with tomatoes, cheese, lettuce and sour cream.