1. Preheat grill to 350° to 400° (medium-high) heat. Cut onion into 3/4- to 1-inch slices. Brush onion slices with 1 Tbsp. olive oil, and season with sea salt and freshly ground pepper to taste. Grill onion slices, without grill lid, 3 to 4 minutes on each side or until tender and lightly charred.
2. Preheat oven to 425°. Lightly dust work surface with cornmeal. Stretch dough into a 10- to 12-inch oval on work surface. Place dough, cornmeal side down, on a greased baking sheet; drizzle with remaining 2 Tbsp. olive oil. Rub oil into dough. Arrange fig halves and grilled onion over dough, pressing lightly. Sprinkle with rosemary and salt and pepper to taste.
3. Bake at 425° on lowest oven rack 15 to 20 minutes or until golden.