Lightly whisk the eggs in a small bowl. Add three pinches of salt.
Drain and pat-dry the roasted pepper. Thinly slice the mozzarella.
Heat 1 Tbsp olive oil in a non-stick frying pan. Add the egg, letting it spread out.
Put the mozzarella slices on the top, letting them sink in a bit. Cook for 3-5 minutes until the cheese has melted and egg is almost set.
Put the roasted pepper on one half of the omelette, season with pepper and chilli flakes, then scatter the spinach over the pepper. Put a lid on and cook under steam for 3 minutes or so until the spinach has wilted.
Carefully fold the omelette in half (the thinner part on top of the layered part). Cook for a few seconds, then slide it to a plate and serve with rocket salad dressed with olive oil and balsamic vinegar.