Wash the potatoes thoroughly and cook in plenty of boiling water for about 30 minutes
Peel and finely dice the onions and garlic. Wash or clean and shine the mushrooms. Cut them into small pieces. Heat 2 tablespoons of oil in a large pan. Sauté half of the mushrooms for about 3 minutes, add half of the onions and garlic and fry again for about 1 minute. Season to taste with salt and pepper. Fry the rest of the mushrooms in 2 tbsp. oil as well. Put all mushrooms back into the pan. Cut the cress from the bed and mix it with the mushrooms
Peel the shallots and cut into thin slices. Wash apple, grate dry, quarter, remove core and cut apple quarters into small cubes. Wash thyme, shake dry and chop coarsely. Heat 4 tablespoons of oil in a pot, sauté shallots in it, add apple and steam for about 2 minutes. Deglaze with vinegar, bring to the boil again and season to taste with salt. Mix in thyme
Drain the potatoes, cut lengthwise, break open and season with salt. Arrange 2 potatoes on each plate, fill with mushroom ragout or apple ragout