Make ahead and reheat in the microwave in a
covered dish for 3-4 mins on High.
Fry the pancetta in a large non-stick frying pan for 4-5 mins until crispy and golden, then add the Brussels sprouts and cook for a further min. Pour in the chicken stock and simmer for 15-20 mins until the sprouts are tender and the stock has reduced. Melt in the butter, season well and serve.