Fast-food mogul Julian Metcalfe, known for his successful ventures in Itsu and Pret A Manger, is set to join the board of Knoops, a rapidly expanding retailer of chocolate-based drinks. It has been reported that Knoops, currently in the process of raising £5m to support its growth, will officially announce the appointment of Mr. Metcalfe as a non-executive director. Mr. Metcalfe…