Prep the ingredients: Crack the eggs into a bowl. Add a pinch of salt, pepper, and the milk or water if using. Whisk with a fork until the mixture looks smooth and slightly frothy. Chop the spinach and onion, and crumble the feta.

Warm the pan: Set a nonstick or well-seasoned skillet (8 to 10 inches) over medium heat. Add the olive oil or butter. You want it warm enough to gently sizzle the aromatics, not scorch them.

Sauté the aromatics: Add the onion. Cook 1–2 minutes, stirring, until soft and translucent. Add the garlic and cook 20–30 seconds, just until fragrant. Sprinkle in oregano or dill. Don’t brown the garlic—it can turn bitter.

Wilt the spinach: Add the chopped spinach to the pan with a pinch of salt. Toss until wilted and most moisture evaporates, about 1–2 minutes. Spread the mixture into an even layer.

Pour in the eggs: Lower the heat to medium-low. Pour the whisked eggs over the spinach. Tilt the pan to distribute evenly. Let the edges set for 10–20 seconds.

Create soft curds: With a spatula, gently pull the set edges toward the center, tilting the pan so uncooked egg flows to the edges. Do this around the pan 2–3 times for a tender, even base. Keep it slow; you’re not scrambling.

Add the feta: When the top is still a bit glossy but mostly set, scatter the feta and a pinch of red pepper flakes over one half. This keeps the omelette creamy inside.

Fold and finish: Use your spatula to fold the omelette in half over the feta. Cook another 20–40 seconds, just until the center is soft but not runny, and the outside is set. Avoid overcooking; eggs continue to firm up off the heat.

Serve: Slide onto a plate. Add a squeeze of lemon if you like, plus extra herbs and black pepper. Eat right away while it’s hot and fluffy.