After 2 minutes, open the grill and check underneath the dough to see if it is getting browned. If it is on one side, but not another, use a spatula or tongs to rotate the dough 90 degrees and cook for another minute. If it is not beginning to brown, cover the grill and continue to cook a minute at a time until the bottom has begun to brown. It should only take a couple minutes if you have a hot grill. The top of the pizza dough will start bubbling up with air pockets.