Prep everything first. Crumble the feta, rinse and dry the spinach (use a salad spinner or pat dry thoroughly), crack the eggs into a medium bowl and season with a pinch of salt and a few grinds of black pepper. Prepping ensures quick, controlled cooking—eggs cook fast and you don't want to be handling raw bacon or greens while the pan is hot.

Cook the bacon until crisp. Place a 10–12 inch skillet over medium heat and add the bacon slices in a single layer. Cook 3–5 minutes per side (depending on thickness) until golden and crisp. Rendering bacon slowly lets the fat melt out, producing crisp texture and flavorful drippings that you can taste in the finished omelette. Transfer bacon to a paper-towel-lined plate and reserve 1–2 teaspoons of the bacon fat in the pan if you like an extra flavor note; otherwise wipe the pan and use butter for a cleaner butter-forward flavor.

Wilt the spinach in the pan. Lower the heat to medium-low, add the butter (and the reserved bacon fat if using) and when it foams, add the spinach. Sauté 30–60 seconds until just wilted. Cooking spinach briefly concentrates its flavor and removes excess water that could make the omelette soggy—this step keeps the eggs light and prevents watery pockets.

Chop the bacon. While the spinach cools for a moment, chop the crispy bacon into bite-sized pieces. This lets the bacon stay crispier in the omelette rather than turning chewy when folded inside.

Beat the eggs gently. Using a fork or whisk, beat the eggs just until the whites and yolks are combined and slightly frothy (about 10–15 seconds). Do not overbeat; you want a uniform color and a little air for tender eggs, but overbeating can make them gummy.

Heat the pan for the omelette. Use a clean nonstick or well-seasoned 8–10 inch skillet and place it over medium-low heat. Add a small pat of butter and swirl to coat. Getting the heat right (moderate rather than high) is key: you want the eggs to set gently so they stay tender and fold easily without browning too much.

Pour and gently stir. Pour the beaten eggs into the pan and let them sit undisturbed for 10–15 seconds; then, with a silicone spatula, gently pull the cooked edges toward the center while tilting the pan so the uncooked eggs flow to the edges. This technique produces even curds and a creamy interior—think soft scrambled texture contained in a classic omelette shape.

Add fillings at the right moment. When the eggs are mostly set but still slightly glossy on top (about 60–90 seconds), distribute the wilted spinach evenly over one half, sprinkle the crumbled feta, and scatter the chopped bacon. Adding the fillings while the eggs are still slightly runny allows them to warm through without overcooking the eggs or melting the feta completely—retaining texture contrast.

Fold and finish. Slide a spatula beneath the opposite half of the eggs and fold the omelette over the fillings to form a semicircle. Let the omelette rest in the pan for 20–30 seconds so residual heat melts the feta slightly and finishes cooking the interior. Gentle finishing heat ensures a creamy center rather than dry, chalky egg.

Plate and season. Slide the omelette onto a warm plate, top with a final grind of black pepper and a small sprinkle of flaky sea salt if desired to lift the feta’s briny edges. Serve immediately so you get the contrast of crisp bacon, creamy egg, and bright spinach.