Whisk together the chickpea flour, water, ground flaxseed, extra virgin olive oil, sea salt, and nutritional yeast until the mixture is smooth. Stir in the tomato, basil, and onion. Then break apart whatever cheese you’re using into small fistfuls and add about 4 of those to the mixture.
Grease the skillet, and add the chickpea omelette mixture. I like to lift the pan and tilt it from side to side so it spreads out in an even layer. Cook over medium heat until the batter is almost firm. Then flip over and go over the omelette with a spatula, pressing it down against the pan. Cook until the bottom begins to smoke (this indicates it is no longer wet).
You are now done. Enjoy!