For the potato and porcini soup, heat the olive oil with butter and add the finely chopped onion.
Sauté briefly, add the potatoes cut into cubes and fry briefly. Pour in soup or water (with soup seasoning).
Season with salt and pepper and cook until the potatoes are crisp.
Add the finely chopped mushrooms to the potato and porcini soup and season with thyme, ginger and whipped cream.