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 edge is crisp and browned and center just begins to brown, 5-7 minutes.
Cut into wedges. Top with optional ingredients as desired.
