Spread open the puff pastry sheet, smear with the Maille Mustard, evenly sprinkle the Gruyere cheese and place the sundried tomatoes and basil over the cheese evenly from one side to the other.
Roll lengthwise to close the pastry, cut in diagonals and place flat on a baking tray, drizzle with olive oil, sprinkle with basil and bake in the middle of a pre heated oven at 350°F until golden brown.