Heat the oil and butter in a heavy based pan over a high heat. Add the onion and garlic and cook until soft and tender.
Add the sliced mushrooms, salt, pepper and thyme to the pan and cook until the mushrooms have browned a little and soaked up the fat in the pan and then begin to omit their juices back into the pan.
Tip in the barley and stir through the juices in the pan for a moment. Add the white vermouth and allow to bubble for away for a moment before stirring in the stock.
When it begins to bubble, reduce heat, put lid on and simmer on a low heat for 25 - 30 minutes until almost all the liquid has been absorbed and barley is tender.
When cooked, turn off the heat and stir through the grated parmesan and cream cheese to make thick and creamy. Check seasoning. Spoon out onto a serving plate or bowl and scatter with chopped parsley.