In a bowl, combine 2 cups (16 fl oz/500 ml) water, the 1¾ cups (7 oz/220 g) flour, 1½ tablespoons oil, the rosemary, ¾ teaspoon salt, and a generous amount of pepper. Whisk until smooth. Preheat the oven to 325°F (165° C). Line 2 large baking sheets with parchment paper and brush lightly with oil. Lightly brush a 10-inch (25-cm) nonstick frying pan (with a 7½-inch/19-cm base) with oil and warm over medium-high heat until very hot. Add about one-fourth of the batter and swirl to coat the pan. Cook until air bubbles appear on the top and the bottom is brown, about 2 minutes. Using a silicone spatula, turn the socca over and cook until spotted brown on the bottom, about 1 minute longer. Turn over onto the parchment. Repeat to cook the remaining batter, forming 4 total. Bake for 5 minutes to cook through and serve, or arrange toppings on socca and bake according to the recipe directions. Makes 4 soft socca.