I do the same thing with the sliced fennel here as I do with my onions: – I toss it with a little olive oil and grill it first in a perforated pan before I grill the pizzas.
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 marinara sauce (no more than 1/4¼ cup) and a layer of fennel. Arrange the olives, if using, here and there, and sprinkle with thyme and Parmesan. 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. Sprinkle with torn or cut basil leaves. Cut into wedges and serve. Repeat with the other two crusts.