01 - Preheat oven to 375°F. Lightly grease a 12-cup muffin tin with cooking spray or oil.
02 - Cut tortillas into circles approximately 4 inches in diameter. Press each circle firmly into a muffin cup, shaping it to form a shell. If using wonton wrappers, place one wrapper per cup.
03 - Bake the tortilla cups for 5-6 minutes until just beginning to crisp. Remove from oven but leave in the muffin tin.
04 - Heat a skillet over medium heat. Add ground beef and cook, breaking apart with a spoon, until browned completely. Drain excess fat if necessary.
05 - Stir in chopped onion and garlic. Cook for 2 minutes until softened. Add taco seasoning and tomato sauce, stirring well to combine.
06 - Reduce heat to low and simmer for 3 minutes until sauce slightly thickens. Remove from heat.
07 - Spoon beef mixture evenly into the tortilla cups. Top each cup with shredded cheddar cheese. Return to oven and bake for 7-8 minutes until cheese is melted and cups are golden brown.
08 - Let cool in the tin for 2 minutes. Carefully remove taco cups using a small spoon or offset spatula.
09 - Top each cup with sour cream, diced tomatoes, cilantro, black olives, and jalapeño slices as desired. Serve immediately while warm.