Heat a large skillet over medium-high heat. Add the ground beef and cook, breaking up with a spoon, until no longer pink, about 5–6 minutes.

Drain excess fat, then return the beef to the pan.

Sprinkle in chili powder, cumin, smoked paprika, garlic powder, dried minced onion, black pepper, salt, and optional red pepper flakes. Stir until the spices evenly coat the meat.

Pour in water, stir, and bring to a gentle simmer. Reduce heat to medium-low and cook for 4–5 minutes, until the sauce has thickened and clings to the beef.

Remove from heat. Spoon the seasoned meat into taco shells or tortillas and top with shredded lettuce, diced tomato, cheese, sour cream, or your favorite garnishes.