Preheat the oven to 375°F.
In a frying pan, cook beef and onion over medium-high heat until no pink remains. Drain any fat.
Add taco seasoning mix and water to the pan and simmer for 4-5 minutes or until thickened. Remove from the heat and allow to cool slightly, toss with 1 cup of cheese.
Unroll the crescent rolls and place them on a parchment-lined pan so that the short end is inside and the tips point out in a circle, resembling a sunshine shape. The center should be 4 inches wide.
Spoon the taco meat mixture over the center of the crescent rolls and top with the remaining cheese.
Fold each dough triangle up over the filling and tuck the tip under the bottom of the circle.
Bake for 20 to 25 minutes, or until the crescent rolls are lightly browned. Cool for 5 minutes, then slice and serve with your desired toppings.
