Preheat oven to 375°F (190°C) and grease a 12-cup muffin tin.
In a skillet, brown ground beef over medium heat until fully cooked. Drain excess fat.
Add taco seasoning and water to the beef. Simmer until the liquid is mostly absorbed.
Press one wonton wrapper into each muffin cup. Add a spoonful of beef, a bit of salsa, and a sprinkle of cheese.
Layer a second wonton wrapper on top and repeat with more beef, salsa, and cheese.
Bake for 15 minutes until the edges are crispy and cheese is melted.
Top with sour cream and green onions before serving.