In a small bowl, whisk chickpea flour, water, 1 tablespoon oil and salt until smooth. Let stand 30 minutes. , Meanwhile, preheat broiler. Place a 10-in. cast-iron skillet in oven until hot, about 5 minutes. Add remaining 1 tablespoon oil to the pan; swirl to coat. Pour batter into the hot pan and tilt to coat evenly. , Broil 6 in. from heat until edges are crisp and browned and center just begins to brown, 5-7 minutes. Cut into wedges. If desired, top with optional ingredients.