Soak a slice of white bread in milk for 5 minutes.
Saute the onion and garlic in a frying pan in a splash of olive oil until soft and translucent. Add the masala and cook for a few seconds. Remove from the heat and allow to cool to room temperature.
In a large bowl, combine the soaked bread, beef, onions, chutney, Worcestershire sauce, vinegar, salt and pepper and mix well.
Place the puff pastry on a lightly floured surface. The sheets I use are approximately 40cmx20cm so I slice them down the center to create two long strips of pastry, approximately 10cm/5inches wide.
Place the meat down the center of the strips of pastry then fold over the pastry, encasing the filling. Pinch the edges together. With a sharp knife, slice into 2-3cm/1inch thick sausage rolls.
Place the sausage rolls on a sheet pan lined with parchment paper. Brush with beaten egg and sprinkle with sesame seeds.
Bake for 15-20 minutes until golden brown and crisp. Remove from the oven and allow to cool for 10 minutes before serving.