01 - Combine chili powder, cumin, smoked paprika, garlic powder, onion powder, oregano, salt, black pepper, and red pepper flakes in a small bowl. Mix thoroughly and set aside.
02 - Heat a large skillet over medium-high heat. Add ground beef and cook for 5–7 minutes, breaking apart with a wooden spoon, until fully browned and cooked through. Drain excess fat if desired.
03 - Sprinkle the prepared seasoning blend evenly over the browned beef. Stir continuously for 1–2 minutes to coat meat thoroughly and toast the spices.
04 - Pour in tomato sauce and 1/4 cup water. Reduce heat to medium-low and simmer for 4–5 minutes, stirring occasionally, until sauce thickens and coats the beef. Adjust seasoning to taste.
05 - Heat tortillas in a dry skillet over medium heat for 30 seconds per side until warm and pliable, or microwave in batches of 2 for 20 seconds wrapped in damp paper towels.
06 - Spoon seasoned beef into center of each tortilla. Layer with lettuce, tomatoes, cheese, onion, and cilantro. Top with sour cream and serve with lime wedges for squeezing.