Here's the illustration of the technique used to cinch plastic around a semi-squishy food product to help with keeping the shape of it nice and uniform and solid. Again, most of you folks with significant food preparation experience will be familiar with this technique, but I am including it for those who may not and because in my opinion, this technique is an important part of making a wrapped fatty like this or many other similar food products stay together while cooking.
Pretend the PVC tube is your food roll, spread out a long length of plastic wrap that is wider than the food... use two pieces laid side by side with at least a 3" overlap if you need to and put the food roll on it like so:
Then fold one end of the plastic wrap over the food like so:
Slide the edge of a thin cutting board or cookie sheet or sheet pan over both layers of plastic and between the work surface and the food roll at an angle like so:
Then tug gently on the bottom (longer) end of the plastic wrap, keeping the board on or very close to the work surface and even pushing in the opposite direction with the board while you pull on the plastic wrap. The board/sheet pan will hold the top layer of plastic from slipping as long as you don't pull too hard and the bottom layer will slide against it, snugging the plastic wrap nicely around the food roll. Then when the plastic wrap is tight enough around the food, just gently drag with the edge of your board or sheet pan towards yourself to stick the plastic wrap layers to each other so the wrapping won't slip and stays snug. Then roll the plastic wrap the rest of the way around the food. This helps it to retain its shape for the cooling periods between steps and before cooking. You COULD use a piece of plastic that is much wider than the food roll and just roll the food up and twist the ends of plastic that are hanging over like taffy and sung it up that way, but in this particular case, that would have been a much more difficult task given the fact that I don't have "restaurant size" plastic wrap and given the size of the fatty, than using the board as I have shown here.