Heat half the oil in a wide, deep frying pan over a medium-high heat. Tip in the mushrooms and cook for around 10 mins until deeply browned, giving them the occasional stir. Tip into a bowl and set aside. Pour the remaining oil into the pan and stir in the onion and garlic, cook for 5-7 mins on a medium heat until slightly softened.

Stir in the flour, mustard powder and both paprikas, and cook for a couple of mins. Slowly pour in the white wine, bit by bit, stirring well after each addition. Bring the wine to a simmer and cook until reduced by half. Pour in the stock and the Jord oat drink and return the mushrooms to the pan. Simmer for 15-20 mins until reduced, then season well with salt, pepper and lemon juice. Sprinkle over the parsley and serve with rice, if you like.