Crack the eggs into a small bowl and whisk until the mixture is smooth and slightly frothy, about 30 seconds.
Heat a non-stick skillet over medium heat and add the olive oil, swirling to coat the bottom. When it shimmers and starts to gently crackle, you're ready.
Add the chopped spinach to the pan and sauté for 1-2 minutes, stirring gently until wilted and vibrant green. The spinach should be tender and slightly shriveled.
Pour the beaten eggs evenly over the sautéed spinach, tilting the pan slightly to distribute the eggs if needed. Let cook undisturbed for about 1-2 minutes, until the edges start to turn golden and set.
Sprinkle the crumbled feta evenly over the eggs. Reduce the heat to low and continue cooking for another 2-3 minutes, until the eggs are just set but still tender on top.
Gently lift the edges with a spatula, tilting the pan to let any uncooked eggs flow underneath. For a fluffier omelette, you can cover the pan briefly for about 30 seconds.
Once the top is just set and slightly jiggly, remove the skillet from heat. Let it rest for a minute to finish cooking gently and settle the flavors.
Slide the omelette onto a plate, fold if desired, and garnish with fresh herbs or a squeeze of lemon for brightness. Serve immediately and enjoy the vibrant, tender bites.
