Peel large beets, cut into thin circles, and then boil with the rest of the ingredients until tender.
Bake the parsnips until cooked, then fry with the addition of chopped onions, pour in the vegetable broth and cook until softened, then pass through a vertical blender until smooth. Mushrooms champignons cut into large cubes and fry well, then add parsnip puree.
Put mashed potatoes on a plate on three sides, place three circles of beets on top, put three hot potatoes with garlic oil, rolled in dry chopped parsley, next to them. Garnish with vinaigrette dressing mixed with grainy mustard.