I use a perforated grill pan to cook sliced onions and other vegetables on the grill. They’ll have a nice charred flavor and be just soft enough if you cook them before you put them on the pizza.
03Lift up the grill lid. The surface of the dough should display some big air bubbles. Using tongs, lift the dough to see if it is evenly browning on the bottom. Rotate the dough to assure even browning. Keep it on the grill, moving it around as necessary, until it is nicely browned, with grill marks. Watch closely so that it doesn’t burn. When it is nicely browned on the bottom (it may be blackened in spots), use tongs or a spatula to slide the dough onto the baking sheet or peel, and remove from the grill. Cover the grill again.
04Make sure that there is still some flour on the peel or baking sheet and flip the dough over so that the uncooked side is now on the bottom. Brush the top lightly with oil, then top with a thin layer of tomato sauce (no more than 1/4¼ cup) and a layer of grilled sliced onions. Sprinkle with thyme and feta, and drizzle on a little more olive oil. Slide the pizza back onto the grill. If using a gas grill, reduce the heat to medium-high. Close the lid and cook for 2 to 3 more minutes, until the bottom is brown. Open the grill and check the pizza. The top should be hot and the bottom nicely browned. If the bottom is getting too dark but the pizza still needs a little more time, move it to a cooler part of the grill and close the top. Use a spatula or tongs to remove the pizza to a cutting board. Cut into wedges and serve. Repeat with the other two crusts.