Heat the sunflower oil in a large saucepan over a medium-high heat for 1-2 minutes. Saute the onion with some seasoning for 2-3 minutes, stirring occasionally, until it starts to soften. Add the garlic and reduce the heat to medium.
Cook for a further 4-5 minutes then increase the heat and add the mince, browning well all over for 8-10 minutes. Add the bay leaf, stir, then add the beef stock and water if necessary to cover the mince. Simmer gently for 20 minutes.
Meanwhile, roll the puff pastry on a lightly floured surface and cut into a 30 cm x 30 cm square with a thickness of ½cm. Reserve the cuttings.
Pre-heat the oven to 200°C.
Spoon the beef onto the middle portion of the pastry, leaving a 10 cm border on either side and 3-4 cm at the ends.Top with the crumbled roquefort and then fold the 10 cm borders in on top of the cheese, one after the other, and seal the edges well using your hands. Arrange the cuttings in the shape of triangles on top and brush with the beaten egg.
Bake for 20-25 minutes until golden brown and risen. Remove from the oven and slice the end before serving.