Combine chickpea flour, water and salt. Mix well. To that add 1 1/2 tbsp of oil

Allow batter to rest for 2 to 3 hours

Add 1 tbsp oil to the cast iron skillet. Preheat the cast iron skillet under the broiler for 2-3 minutes. 

Carefully remove (very) hot skillet from oven.Pour enough batter into the skillet to barely cover the bottom. Swirl the batter to coat the whole pan. (When I make this I use a small 6" skillet and use approx. 1/3 c. of batter.) 

Place the cast iron skillet back under the broiler and bake for 3 to 4 minutes. 

Carefully remove the hot pan from the oven. Carefully remove baked socca from the pan. 

Carefully oil the pan again and cook the remaining batter.