In a medium mixing bowl, combine chickpea flour with salt, baking powder, garlic powder, Parmesan cheese and ½ cup water. Whisk well adding more water to achieve a thin but not watery batter. Cover and let rest for at least 15 minutes (could be up to 12 hours)

In the meantime, heat oven to 425425℉ (204 C). Preheat the cast iron skillet. Place toppings of choice, sliced onions, chickpeas and mushrooms into a baking pan, drizzle with 1 teaspoon EVOO and place in oven. Once the batter has rested, add the basil and stir to combine.

Add 2 teaspoons EVOO to hot pan. Pour in batter and move the pan around to allow batter to flatten like a pancake. Transfer skillet to the oven and bake 10-15 minutes until bubbles form and edges have browned.

Remove socca and toppings from oven and allow to cool slightly.

Loosen socca and place on cutting board. Spread pesto and top with roasted chickpeas, mushrooms and onions. Sprinkle over arugula, salt and pepper. Cut into pieces and serve.