In a large skillet over medium heat, add the ground beef and cook until browned, breaking it apart with a spatula as it cooks. This should take about 5-7 minutes.

Drain any excess fat from the skillet.

Add the diced onion and minced garlic to the skillet, stirring them into the beef. Cook for an additional 2-3 minutes until the onion is translucent.

Stir in the taco seasoning and water. Bring the mixture to a simmer and let it cook for about 5 minutes, allowing the flavors to meld and the sauce to thicken slightly.

While the beef is cooking, prepare the taco shells according to the package instructions, usually by warming them in the oven or microwave.

Once the beef mixture is ready, assemble the tacos by filling each taco shell with a generous scoop of the beef mixture.

Top the beef with shredded lettuce, diced tomatoes, and shredded cheese.

Add a dollop of sour cream and a spoonful of salsa on top of each taco.

Garnish with fresh cilantro if desired, and serve immediately.