Sort the spinach, wash and drain. Peel onion and garlic, chop finely
Heat the oil. Sauté onion and garlic in it. Add the spinach and sauté or heat up frozen spinach. Season with salt, pepper and nutmeg
Peel and wash the potatoes and slice them into very thin slices. Clean, wash and halve the tomatoes. Layer spinach, potatoes and tomatoes in an ovenproof dish. Season with salt and pepper
Mix cream and milk and pour over the vegetables. Bake the gratin in a preheated oven (electric cooker: 200 °C / convection oven: 175 °C / gas: level 3) for approx. 1 hour
Crumble the cheese or cut it into cubes. Sprinkle over the gratin after about 30 minutes
Drink: cool rosé wine