Heat the clarified butter, add the mince and brown for approx. 3 mins. Reduce the heat, add the leek and broccoli and fry for approx. 4 mins. Stir in the mustard, cream and stock, season. Divide the finished mixture into an oven-proof dish of approx. 2 litre capacity (approx. 28 cm diameter).
Coat the rim the dish with a little of the egg & milk mixture. Firmly prick the dough with a fork, lay on top of the mixture, press the edges down firmly and coat with the egg & milk mixture.
Bake for approx. 30 mins. in the centre of an oven preheated to 200°C.