A thick chickpea crêpe often found at street carts in the south of France, socca is usually served with the barest of garnishes. We’ve flecked it with fresh rosemary and given it a sprinkling of olives, as you might find it from a stall on the Côte d’Azur.
Whisk the flour and salt together in a bowl. Add the water and olive oil and whisk until smooth. Cover and let the batter rest at room temperature for at least 2 hours.
After 1 hour, place a rack in the center of the oven and preheat it to 500°F.
When ready to bake, liberally oil a 14" deep-dish pizza pan, or two 9" cake pans. Place the pans in the oven to preheat for 5 minutes.
Carefully remove the pan(s) from the oven and pour in the batter. Sprinkle the rosemary over the top.
Bake for 6 minutes, then remove from the oven and sprinkle the olives over the top. Return to the oven for 6 to 8 minutes more, until the surface is a mottled brown. If the top doesn't brown, turn the oven from bake to broil and watch carefully until you see some freckles appear.
Remove from the oven, cool for 5 minutes, then cut into wedges to serve warm. The top and bottom should be crisp, and the center creamy and moist.
Store, covered, in the refrigerator for up to a week. Reheat in a preheated 400°F oven for 10 minutes before serving.
