For the pastry:
Sift the flour into a bowl.
Place the butter and water in a large saucepan over a medium heat, Induction level 6. Bring to the boil then add to the flour and mix quickly to form a soft dough.
Knead on a lightly floured surface then cover and allow the dough to rest while you make the filling.
For the filling:
Dice the potato, carrot and swede into 8mm pieces. Place into a bowl and combine with the onion, cheese, mustard, parsley salt and season well with pepper. Mix well to combine.
Preheat oven on CircoTherm to 200˚c. Line two trays with baking paper.
Divide pastry into 12 even pieces and roll each piece into a 15cm disc. Firmly pack the filling along the centre of each round, leaving approximately 1cm at each end. Brush the edges of the pastry all the way around with the egg. Carefully draw up the pastry edges to meet at the top, then pinch the pastry together to seal.
Place the pasties onto the prepared trays, brush with remaining egg then cut a few vents in each pastie to allow steam to escape.
Bake on shelf positions 1 and 3 for 25 to 30 minutes or until golden and cooked.
Serve with tomato relish.