Wash the plaice and dab dry. Cut pockets on the brown side of the skin from the middle bones to both sides. Place the plaice on a greased baking tray, season with salt and pepper and drizzle some lemon juice into the pockets if necessary. Clean and wash the spinach and blanch in boiling salted water for one or two minutes. Drain spinach well and chop.
Cut toast into fine cubes. Heat 20 grams of butter in a pan and roast the bread cubes in it. Peel garlic and chop finely. Heat 10 grams of butter in a pan and fry the garlic and spinach. Season with salt, pepper and nutmeg. Let cool down a little. In the meantime, scrape potatoes under cold water. Cook potatoes in little boiling salted water for 20 minutes. Mix spinach, bread cubes and prawns and fill the plaice with it. Brush the plaice with remaining butter and roast in the preheated oven (electric cooker: 225 ° C/ gas: level 4) for seven to ten minutes.
In the meantime, scrape potatoes under cold water. Cook potatoes in little boiling salted water for 20 minutes. Mix spinach, bread cubes and prawns and fill the plaice with it. Brush the plaice with remaining butter and roast in the preheated oven (electric cooker: 225 ° C/ gas: level 4) for seven to ten minutes. Wash the dill, dab dry and chop, except for a little to garnish. Arrange plaice and potatoes on plates. Serve sprinkled with dill and garnish