Prep the eggs: Crack the eggs into a bowl. Add the heavy cream if using. Season with a pinch of salt and pepper. Whisk until the mixture looks smooth and slightly frothy.

Warm the pan: Place a nonstick skillet over medium heat. Add the butter and let it melt, tilting the pan to coat the surface.

Wilt the spinach: Add the spinach to the pan. If using garlic, add it now. Cook for 30–60 seconds, stirring, until the spinach softens and any moisture cooks off. Season lightly with salt and pepper.

Add the eggs: Reduce heat to medium-low. Pour the eggs over the spinach and let them sit undisturbed for 10–15 seconds so the bottom sets.

Stir gently: Using a rubber spatula, push the edges toward the center in gentle strokes, letting the uncooked egg flow to the sides. Do this for about 30–60 seconds until the eggs are mostly set but still slightly glossy on top.

Add the feta: Sprinkle the crumbled feta over one half of the omelet. Add red pepper flakes if you like a little heat.

Fold and finish: Carefully fold the omelet in half over the filling. Cook another 20–30 seconds to let the cheese warm and the center set to your preference.

Plate and garnish: Slide the omelet onto a plate. Top with fresh herbs and a crack of black pepper. Serve hot.