Placing the pork loin in the freezer for 15 to 20 minutes before cutting will help you a lot. Just keep in mind you’re not actually trying to freeze the meat. You just want to chill it down so it will firm up and be easier to cut.
Make sure your cutting board is set firmly in place. If it slips around on your counter at all, simply place a doubled up tea towel underneath it. A cutting board slipping around the counter when you’re butterflying a roast is exactly the kind of thing that causes unwanted trips to the emergency room!
For this kind of work I like turning to a fillet knife over a chef’s knife or other traditional knives you might have sitting in the block.
Here is how to make delicious Butterfly a Pork Loin
Step 1: Place the pork loin in the freezer for 15 to 20 minutes.
Step 2: Lay the pork loin out on the cutting board the long way so that it is perpendicular to you. Then carefully trim off any excess fat.
Step 3: Hold the knife parallel to the cutting board and make a shallow slice about half an inch up from the bottom. You want a uniform slice to help with even cooking.
Step 4: Keep making long shallow slices as you pull back the main bulk of the roast with your other hand. Continue until you have one long even sheet of meat.
Step 5 (Optional): If you want a super tender roast, you can lightly wet the surface of the meat and gently pound it out with a smooth meat mallet or rubber mallet. Do not use a spiked meat mallet, as you will damage the roast.