Mix the chickpea flour and water together in a medium sized bowl. Let the mixture sit for at least 2 hours prior to baking.
When you are ready to bake the bread preheat the oven to 375 degrees. Add the nutritional yeast, garlic powder, onion powder, oregano, salt, pepper, and basil to the flour and water mixture. This will be a thin batter.
Rub a large baking sheet with the olive oil and then pour the batter onto the pan. Place the tomato slices on top and carefully place the pan in the oven. Bake the bread 45 - 50 minutes until the edges and top have browned. Make sure the middle of the bread has set completely before removing it from the oven.