Ingredients:
* 2 tablespoons olive oil
* 15 g (1/2 oz) butter
* 250 g (8 oz) mixed mushrooms, such as shiitake and chestnut, rinsed, trimmed and thickly sliced
* 3-4 garlic cloves, crushed
* 125 g (4 oz) oyster mushrooms, rinsed, trimmed and thickly sliced
* 2-3 tablespoons dry sherry or vermouth
* 4 tablespoons chopped fresh parsley
* salt and freshly ground black pepper