In a large skillet, over medium-high heat, add the ground beef and onion. Cook and crumble until beef is no longer pink. Drain grease.

Add the taco seasoning and water to skillet. Stir until mixture comes to a boil. Reduce heat to low and let simmer 10 minutes.

Rinse the lettuce leaves in cold water to clean. Pat dry with paper towels. Take 1/3 cup of meat mixture and place in the center of lettuce leaf. Top with a little shredded cheese, tomato, salsa and sour cream. Enjoy!