Soak the dried porcini mushrooms in boiling water for at least 15 minutes. Slice the field mushrooms into 1 cm slices and thinly slice the Potabellini mushrooms.
Mince the garlic and finely chop the onion. In a large pot, fry the onions in the butter and oil until glassy.
Add the sliced Portabellini mushrooms, garlic and thyme to the onions and fry until the mushrooms gain some colour.
Using the soaking water from porchini mushrooms, bring to the boil and reduce by half then add the Cooking RichTM.
Meanwhile, fry the sliced field mushrooms and reserve for service.
Lightly season the sauce with salt, pepper and lemon juice to taste.
