Heat a heavy saucepan on a medium-high heat. Add 2 tablespoons of olive oil and 1 tablespoon of butter. Add the mushrooms and fry in batches, so as not to overcrowd the pan. Remove them and set aside on a plate when brown at the edges.
Add another tablespoon of oil to the same pan and fry the shallots on a low-medium heat for 6 or 7 minutes until soft. Add the garlic and cook for 2 minutes.
Add the wine and boil down for 2 minutes to a glaze. Then add 300ml of the stock and boil down again for another 3-4 minutes. Add all the mushrooms back in with the rest of the stock and simmer for 5 or so minutes until they are nice and tender.
Add the wine and boil down for 2 minutes to a glaze. Then add 300ml of the stock and boil down again for another 3-4 minutes. Add all the mushrooms back in with the rest of the stock and simmer for 5 or so minutes until they are nice and tender.