Peel, wash and halve the potatoes. Cook in salted water for about 20 minutes
Clean, wash and drain the spinach. Wash and finely chop the dill. Wash the plaice fillets, dab dry and cut in half lengthwise. Place on a work surface with the skin side facing upwards. Season with salt and pepper. Halve the salmon slices. Put 1/2 slice on each fillet, sprinkle with dill. Roll up the fillets and pin them down
Peel and chop the garlic. Peel onions, cut one into slices. Boil up about 3/4 l water, onion slices, lemon juice, peppercorns, salt, sugar and bay leaf in a wide pot. Cook the rolls in it at low heat for about 10 minutes
Chop 1 onion. Fry with garlic in 1 tbsp. hot oil. Add the spinach and let it collapse. Season with salt and pepper
Heat 1/4 l milk and 1 tablespoon butter. Drain, steam, add and mash the potatoes. Season to taste with salt and nutmeg
Lift out the rolls, measure 1/8 l fish stock. Add 5 tablespoons of milk and wine. Stir in sauce powder, bring to the boil. Beat 75-100 g butter in pieces over low heat, season to taste
Pour the puree as a rim into an oiled fireproof mould. Put spinach in the middle. Spread the rolls on top and pour the sauce over them. In a preheated oven (electric cooker: 225 °C/ convection oven: 200 °C / gas: S