Heat the oil in large frying pan puff and cook the onion until softened, add the sage leaves and cook a further minute. Set aside. Add the Magic Mince and parsley into a bowl and mix together with the onion and sage mixture. Season with salt and pepper. Form the mix into long sausage shapes.
Place 2 pastry sheets on 2 lined trays and cut each in half lengthwise. Using the teaspoon, spread mustard in a line along the middle of the 4 sheets. Sprinkle a small handful of cheese on the mustard and place a sausage shape on top and roll it up. Cut into rolls and make a few small horizontal cuts on top. Brush with the egg wash and top with optional sesame seeds.
Bake in the preheated oven at 180C fan bake for 25 min or until the pastry has a nice golden colour.