Start by going over the cracklings with a sharp knife. Often they aren't cut uniformly or deep enough into the fat from the factory. Get your butcher to do it for you, if needed.

Season the roast with salt and pepper on both sides.

Vacuum seal it and cook it for 5 hours at 59 degrees Celsius (138 degrees Fahrenheit) in sous vide. If you think your pork roast is of questionable quality, give it an extra hour.

Take the meat out of the bag and dry it very thoroughly with a clean tea towel. There's a lot of gelatin on top that will work against you in getting crispy cracklings.

Get between every single crackling and dry it as well as possible.

Put coarse salt on top of the roast and deep into the cracklings as well.

Heat your oven to the highest possible temperature (my oven goes to 300 degrees Celsius (572 degrees Fahrenheit), 275 degrees Celsius (527 degrees Fahrenheit) is also fine) and set it to convection. Do not use the grill as it will burn the cracklings.

Place the roast about 3-5 cm from the top and give it 20-25 minutes until all the cracklings are crispy. You don't need to watch the roast for the first 15 minutes, but after that, check it every other minute. It will finish quickly in the end.

The result was a juicy and delicious roast with the most beautiful cracklings on top.

Enjoy the best pork roast of your life!

Note: The juice from the bag can of course be used for gravy, but the "disadvantage" of this cooking method is that not much juice comes out; it stays in the meat :-)