1. To make the cheese sauce, mix the cornstarch to a paste with a little milk. Pour the remaining milk into a nonstick saucepan and bring to a boil. Stir the boiling milk into the cornstarch mixture, then pour back into the pan. Bring to a boil, stirring. Once it has thickened, simmer for 2 minutes. Remove from the heat, stir in the Gruyère cheese, and season with nutmeg and pepper. Cover the surface of the sauce with parchment paper to prevent a skin from forming and set aside in a warm place.
2. Heat the margarine with the oil in a saucepan. Add the leeks and cook for about 3 minutes, until beginning to soften. Add the spinach and stir. Cover the pan and cook over medium heat for 2–3 minutes until the spinach has wilted and the leeks are tender. Drain the vegetables in a sieve, pressing down with the back of a spoon to remove any excess moisture. Return to the pan and season with pepper. Cover and keep warm.
3. Meanwhile, half-fill a large frying pan with water and bring to simmering point. Add the vinegar. Break in the eggs, and cook gently for 3–4 minutes, spooning the hot water over the yolks. Lift out the eggs with a slotted spoon and drain on paper towels.
4. Preheat the broiler. Spread the leek and spinach mixture in an even layer in a large flameproof dish. Make 4 hollows in the vegetables using the back of a spoon and place a poached egg in each hollow. Spoon the cheese sauce over the eggs. Lightly dust with paprika, then place the dish under the broiler. Cook for 3–4 minutes until lightly browned. Serve eggs Florentine at once.

preparation time 10 mins
cooking time 20 mins
serves 4

PER SERVING

278 calories
17 g protein
18 g total fat
5 g saturated fat
224 mg cholesterol
14 g total carbohydrate
7 g sugars
3 g fibre
229 mg sodium

Spinach is a good source of nutrients with antioxidant properties, including vitamins C and E and carotenoid compounds. Leeks belong to the onion family. They provide vitamin E, and the green part of the leek is a good source of beta carotene.