Step 1: Whisk the eggs: Crack the eggs into a bowl, add milk, salt, and black pepper, and whisk briskly with a fork until uniform and slightly foamy. A full 30 seconds of whisking is the key to fluffiness — do not cut corners.

Step 2: Melt butter over low heat: Melt butter in a non-stick skillet over low heat, swirling to coat the bottom. Keep the heat low; add the eggs the moment the butter bubbles, to avoid a bitter scorch. Butter aroma is the soul of the omelette, so wait ten extra seconds rather than let the fat get too hot.

Step 3: Pour and set the base: Pour in the eggs, rest 10 seconds, then gently push the edges inward with a spoon so raw egg flows to the center. Stop when most of the top is set and the bottom is lightly golden.

Step 4: Add fillings and fold: Scatter cheese and spinach over half the egg, then fold the other half over with the spatula. Steam 30 seconds over low heat so the cheese melts. The warm cheese gently glues the filling; fold with a light hand so the egg does not crack.

Step 5: Slide onto the plate: Nudge the omelette onto the plate seam-side down with a gentle push along the pan edge. Finish with cracked black pepper and eat while hot for the tenderest bite.