Whisk together chickpea flour and water until smooth. Add olive oil, salt, pepper and basil. Let the batter rest for at least a few hours at room temperature. I always opt to do this the night before so that it's ready to bake when I wake up!
Preheat the oven to 425 degrees. Coat your cherry tomatoes in 1 tbsp olive oil and sprinkle with salt. Roast for 15 minutes, until they are charred and slightly deflated. This helps remove the moisture so that you don't end up with a watery farinata!
Once the tomatoes are finished, combine with mozzarella and olives in a 10" castiron. Pour the chickpea batter over the fillings.
Bake for 30 minutes. The edges should be slightly browned and completely cooked.