Preheat oven to 375 degrees F.
Brown ground beef and saute onions in the pan together. Drain excess grease. Add taco seasoning, stir together and set aside.
On a pizza pan, arrange the crescent roll triangles in a circle overlapping with the points facing outward hanging off the pan and the center left open.
Spoon the beef mixture evenly around the ring of the dough. Sprinkle 1 cup shredded cheese over top.
Fold the points over and to the center and press to the inner edge to seal.
Bake for 20-25 minutes or until golden brown.
Fill the empty circle with your favorite taco fillings, remaining cheese, lettuce, tomatoes, sour cream, etc. Cut into slices and serve.