Preheat oven to 400° F.

Defrost puff pastry according to package instructions. Roll the pastry out on a floured counter to a rectangle of about 19” x 12”. Cut the large rectangle in half lengthwise, then cut both smaller rectangles into eight equal sections down to 16 rectangles total.

Spread a small amount of mustard on top ⅓ of each pastry rectangle. Lay a half of a hot dog or sausage on the mustard and sprinkle with herb of choice. Brush the other end of the rectangle with a little of the beaten egg and roll the sausage up in the pastry, sealing the ends. Put the sausage rolls in the refrigerator for 15-20 minutes for the pastry to chill.

Remove from the refrigerator and prick the tops with a fork, brush with the rest of the beaten egg, sprinkle with kosher salt and bake in the oven for 25 to 30 minutes, or until the pastry has turned a golden brown and looks crisp. Remove from the oven and serve warm or at room temperature with more mustard.