On a flat work surface area, place a sheet of puff pastry down. Layer 4 slices of meat and 4 slices of cheese over top. Roll the puff pastry up lengthwise so that the meat and cheese is spiraled in between the layers.
Cut the log into half-inch slices and place the rounds onto a baking sheet lined with parchment paper and bake until golden brown and crispy, 10-12 minutes.
Serve the mustard alongside for dipping.