Karen, do you know what I mean by 'triple butterfly'? Just in case...
There are two ways to flatten the pork to make a stuffed roast: butterfly and rolled.
To butterfly a roast, make a parallel cut from one end to the other without cutting all the way through the opposite side. When done, you should be able to open the roast like a book or butterfly.
The other method, rolled cut, takes a while to master. This involves slowly cutting the roast to a consistent thickness while 'unrolling' the remainder. Kind of like unrolling a roll of paper towels, except that you are actually cutting the 'sheet'.
I find it much easier to do a triple butterfly instead of the rolled cut.
Once the three cuts are made, carefully unfold the roast and open it out. Place it on a piece of plastic wrap. Place another piece of plastic over it. Using a meat mallet or
empty wine bottle, flatten out the length of the roast.
At this point, I season the meat and roll it up and let it sit in the refrigerator to chill and allow the seasonings to do their thing.
Depending on what you are going to use for a stuffing, prepare it and make sure it is completely cool before stuffing the roast.
About an hour before serving, remove the roll from the refrigerator and unroll on the cutting board. Leave the plastic wrap on the bottom.
Preheat the oven to 350 degrees.
Place the stuffing on the top side of the roast no more than 1/2 inch thick. (If you've ever made a jelly or swiss roll, you'll totally understand why!)
Using the plastic wrap carefully lift the roast and tightly, but not too tightly, roll it up. As you roll the roast, remove the plastic wrap from the bottom.
If you have kitchen string (100% cotton), tie the roll at 1-inch intervals to hold it together. If you don't have kitchen string, you can also roll it up in a sheet of parchment paper, twisting the ends to seal.
Place the roast in a v-rack (too help hold the shape) in a roasting pan. Roast to an internal temperature of 160 degrees.
If you tie the roast, you will need to periodically baste it as you would a regular loin roast.
If you used the parchment, the roast will not have a brown crust on it, but it will have faint marks from the v-rack.
Allow the roast to rest for a 10 minutes to firm up.
Carefully slice with a very sharp knife using a sawing motion.
Enjoy!