Wash the potatoes and boil in water for about 20 minutes. Then quench, peel and let cool
Clean and wash the spinach. Peel onions and garlic, dice finely. Heat 2 tablespoons of fat. Fry garlic and 2/3 onions until translucent. Add the spinach in portions and let it collapse. Season, drain if necessary. Cut potatoes into slices. Grate both cheeses
Heat 3 tablespoons of fat. Sauté the rest of the onions in it. Sprinkle with flour and sauté. Stir in 3/8 l water, milk and stock. Bring to the boil and simmer for about 5 minutes. Melt half the cheese in it. Season sauce with salt, pepper and nutmeg to taste. Whisk egg yolk and cream. First mix with some sauce, then stir back into the rest of the sauce (do not boil any more!)
Grease a large casserole dish (approx. 35 cm long). Spread some sauce on the bottom of the dish. Layer potatoes, spinach and sauce alternately. Finish with potatoes and sauce. Sprinkle with remaining cheese and pine nuts. Bake lasagne in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for approx. 45 minutes
Prepare Prima
Simply practical: ingredients for the lasagne ready to use
pile up and put in a cool place. If necessary, place in the oven (add some time if necessary)