Pre heat oven to 180 degrees.
Peel and chop/grate the onion and vegetables (if necessary) and potato
Place all vegetables and rosemary into a frying pan with olive oil. Fry and stir for about 8 minutes or until vegetables soften and colour
Put vegetables into large bowl to cool completely
Add the minced beef to the bowl with further seasoning if desired and the egg. Scrunch together
Thaw and roll out pastry. With this recipe it will create 1 large wellington loaf. To do this, lay two sheets lengthways and slightly press to join or roll to create one large double length sheet
Place mince mix along one long side, in a sausage shape
Brush edges of the pastry with egg and roll pastry to cover mince completely. Squeeze ends together. It should resemble one large "loaf"
Put onto a baking tray, brush with remaining egg. Bake for an hour until golden. Slice and serve with gravy if desired