Tomato-Pesto Socca

Whisk flour, salt and pepper in a large bowl. Add water; whisk until smooth. Let rest while the oven preheats or refrigerate for up to 1 day.

Position racks in upper and lower thirds of oven. Place a 12-inch cast-iron skillet on the lower rack. Preheat to 450 degrees F for 30 minutes.

When the oven is preheated, carefully remove the hot pan and swirl in 1 tablespoon oil. Whisk the batter, pour it into the pan and swirl to coat. Top with tomato and mozzarella.

Bake until the bottom is browned and the edges are crispy, 16 to 20 minutes. Remove from the oven and, using a pastry brush, dab the socca with the remaining 1 tablespoon oil (brushing can dislodge the toppings).

Turn the broiler to high. Broil the socca on the upper rack until browned in spots, 1 to 3 minutes. Top with pesto and cut into wedges.