If making pizza dough from scratch, make it a couple of hours ahead and let it rise.
4 large Italian plum tomatoes, sliced thin (juice from sliced tomatoes reserved)
2 tablespoons olive oil, divided
3 garlic cloves, minced
1 pound store bought or 1/2 recipe homemade pizza dough
Salt and ground black pepper
3 ounces (about 3/4 cup) grated mozzarella cheese)
4 cups packed arugula or baby spinach
1/4 cup coarsely chopped kalamata olives
2 ounces crumbled feta (about 1/2 cup)
1. Turn all burners of a gas grill on high or build a charcoal fire. Meanwhile, lay sliced tomatoes on a baking sheet. Mix 1 tablespoon of the oil with the minced garlic. Drizzle oil over tomatoes; set aside.
2. Without punching or kneading dough (which makes stretching more difficult), turn dough onto a lightly floured surface. Using a dough scraper or sharp knife, quarter dough crosswise. Working one at a time, stretch each portion into a rustic 12- by 3 1/2- to 4-inch rectangle; transfer to a large cornmeal-coated baking sheet.
3. Reduce grill heat to medium; lift stretched pieces of dough on grill. Cover and cook until bottoms are spotty brown, moving them around and punching dough down as necessary to ensure even cooking, 3 to 4 minutes. Return pizza crusts, grilled side up, to baking sheet, topping each with a portion of tomatoes (pouring any remaining garlicky tomato liquid onto salad greens. Lightly sprinkle tomatoes with salt and top with a portion of mozzarella cheese. Return pizzas to grill; cover and continue to grill until pizza bottoms are spotty brown, 3 to 4 minutes longer. Transfer to a cutting board.
4. Meanwhile, toss arugula with olives, feta, remaining tablespoon of oil and a light sprinkling of salt and pepper. Drizzle in reserved tomato juice; toss to coat again. Top each pizza with a portion of salad; Transfer to a cutting board, cut into pieces and serve.