Preheat a skillet on the stovetop to medium heat. Add a tablespoon of olive oil and roll the pan around until the oil is evenly spread.
Pour 1 heaping cup of sourdough starter into the skillet. You may need to use an offset spatula to help spread the starter around the skillet. Adjust the heat to medium-low.
Add a pinch of salt. When the flatbread is beginning to bubble on the top and the edges are set, flip the entire flatbread over.
Put the tomato sauce or diced tomatoes, shredded cheese, and seasonings on the flatbread.
Cover the skillet with tented tinfoil or a lid that is offset to allow steam to escape. Steam is the enemy of the crispiness you’re looking for.
If you are trying to make several that you want to be done at the same time, you can take the flatbread off of the skillet and put it on a baking sheet. When the baking sheet is full, you can put it in a preheated oven until the toppings are melted or blended.