Clean the mushrooms with a brush or dry kitchen paper and cut them in half or quarters, depending on size. Peel and finely dice the garlic and onion.
Fry the mushrooms in a large dry non-stick pan for 4-5 minutes, turning frequently. Add the oil, onion and garlic and fry for 2 minutes.
Add the tomato puree and fry briefly. Add the paprika then the stock and soy cream.
Place the baby onions in the frying pan, bring to the boil, then reduce the heat, cover and simmer for 4 minutes. Wash the sage and chives, shake dry and pick off the sage leaves.
Finely chop the chives, chop the sage and add both to the sauce. Season with salt and black pepper and serve hot.