Slice the zucchini into 3 mm rounds. Mince the onion.
Heat a decent amount of oil in a frying pan, and stir-fry the zucchini until it's soft. Add onions midway, and continue to cook until it's slightly browned.
Transfer the cooked ingredients into a bowl. After they cool down slightly, crack and beat the eggs. Taste, and season with salt and pepper.
Heat a decent amount of oil in a frying pan, and pour in the mixture from Step 3. Use a plate to flip it over. Cook until it's nicely browned to finish.
Story Behind this Recipe
This is a dish that I ate at a Spanish bar. With the sweetness of the zucchini and onion, it has a slightly different taste than potato omelettes.
When cooking the omelette in Step 4, use a decent amount of oil and heat it as if you're frying the eggs for a fluffier result. Please refer to my "Potato Omelette [Recipe ID: 616135]" for instructions on how to flip the omelette over with a plate.