For the puree, peel and wash the potatoes, cover and cook in salt water for about 20 minutes.
For the spinach, peel and chop the onion and garlic. Heat 1 tablespoon of oil in a pot. Fry the onion and garlic in it. Add the frozen spinach and 5 tbsp. water and simmer covered over medium heat for about 15 minutes.
For the medallions, pat the meat dry, cut into 8 medallions and tie them into shape if necessary. Season with salt and pepper. Heat 1 tablespoon of oil in a large ovenproof pan. Sauté the medallions in it for about 1 minute on each side.
Bake the medallions in a pan in a preheated oven (electric cooker: 175 °C/circulating air: 150 °C/gas: see manufacturer) for approx. 8 minutes. Cut the camembert into thin slices, place them on the medallions after approx. 3 minutes and bake until done.
Stir the cream into the spinach and heat. Season to taste with salt and pepper. Drain the potatoes. Add milk and butter and mash finely. Season to taste with salt and nutmeg.
Arrange everything and garnish with cress.