Cut the cucumber into rounds that are a 1/4 inch (0.625 cm) thick, then add them into a colander with a bowl underneath, season with salt, and set aside

Roughly chop the onions, roughly chop the garlic, and crack the eggs into a large bowl, then add in the chopped chives and season with salt & pepper, whisk together until well mixed

Heat a large fry pan with a medium heat and add in the olive oil, after a couple of minutes, add in the chopped onion, mix together, then mix every 1 to 2 minutes so everything evenly sautés

In the meantime, move back to the cucumber slices, transfer them over some paper towels, all in a single layer, and pat completely dry, if you have too much salt on the cucumber, just wipe some of it off

After sautéing the onions for 6 to 8 minutes and they're lightly sautéed, add in the slices of cucumber, mix together, then mix every 1 to 2 minutes

Once the slices of cucumber are lightly sautéed, about 4 minutes, add in the chopped garlic and season with black pepper, mix continuously, after 1 minute and the garlic is fragrant, remove the pan from the heat and transfer the mixture into the bowl with the whisked eggs, making sure to reserve the olive oil in the pan, mix together and let it rest for 3 to 4 minutes

In the meantime, heat a 24 cm (9.5 inches) nonstick frying pan with a low-medium heat, and add in the reserved olive oil from the vegetables

After a couple of minutes, add in the cucumber and egg mixture, making sure it's all in a flat layer, and cook for 3 to 4 minutes without mixing

After 3 to 4 minutes it's time to flip the omelet, using a plate that is slightly smaller than the pan, place it over the omelet, and in one swift move, flip the pan into the plate, then slide the omelet back into the pan and compact it from the outer edges toward the center, cook for another 3 to 4 minutes or until the eggs are just cooked through, then remove from the heat

Gently slide the omelet into a serving dish, serve warm, at room temperature, or even chilled, enjoy!