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 180°C fan bake for 25 min or until the pastry has a nice golden colour.