01 - Heat olive oil in a large skillet over medium heat. Add ground beef and cook, breaking up the meat with a spatula, until browned, about 5 to 6 minutes.
02 - Drain excess fat if necessary. Stir in chili powder, smoked paprika, cumin, garlic powder, onion powder, salt, black pepper, and cayenne. Cook for 1 minute until fragrant.
03 - Add tomato paste and water; stir to combine. Simmer for 3 to 4 minutes until thickened. Adjust seasoning to taste.
04 - While beef cooks, wash and dry lettuce leaves. Arrange them on a platter to form taco shells.
05 - Spoon the seasoned beef mixture evenly into each lettuce shell.
06 - Top each taco with shredded cheddar cheese, diced red onion, diced tomatoes, chopped cilantro, sliced avocado, and a dollop of sour cream.
07 - Serve immediately with lime wedges on the side.