For the potato salad with chanterelles and white beans, boil the potato with the skin until firm to the bite, then peel and cut into thin slices while still warm.
For the marinade, peel the onion and cut into small cubes. Bring the onions to a boil with the stock, vinegar, mustard, salt and sugar and pour hot over the potatoes. Stir carefully until the salad becomes creamy.
Clean the chanterelles and fry them in a hot pan until the water evaporates. Add the beans and toss well, pluck the parsley from the stalk and wash well.
Mix the mushrooms and beans with the potato salad and parsley and season again with olive oil, salt and pepper.
Garnish the potato salad with chanterelles and white beans with quartered cherry tomatoes.