Rub the salt and black pepper evenly over the surface of the pork. Sprinkle with the rosemary leaves too.
Put the seasoned pork and olive oil in a ziplock bag, and massage the meat well over the bag. Use a straw to eliminate as much air as possible from the bag, then seal it up tightly.
Leave to marinate in the refrigerator for 2 to 3 hours if possible. If you don't have time, leave it in the refrigerator for at least 30 minutes.
Take the pork out of the refrigerator, and leave it out for 30 minutes to an hour so that it can return to room temperature.
Heat up some olive oil (not listed in the ingredients list) in a frying pan, and brown the pork over high heat.
When the entire surface is browned, take the meat out onto a plate and let it rest. Bring a large pot of water to a boil in the meantime.
Turn off the heat once the pot comes to a boil. Add the pork 5 to 10 minutes later. (See Hints.)
Put the pork back in the Ziploc bag, push the air out of the bag and seal it tightly.
Wait 5 minutes after the water comes to a boil, then put the pork in (bag and all). Simmer without a lid over very low heat for 15 minutes. Turn the heat off, cover with a lid and leave the pot for 15 minutes. Take out the pork.
Leave the pork to cool down completely in the bag.
Make the balsamic sauce. Put all the sauce ingredients except for the butter in a small pan, and simmer over low heat to reduce.
When the sauce has reduced a little, add the butter and shake the pan around to gradually combine with the rest of it. When the butter has melted, the sauce is done.
When the pork has cooled down completely, take it out of the ziplock bag and slice. Serve with the sauce!
I used balsamic sauce in this recipe, but please use whatever sauce you like. Store-bought roast beef sauce for instance.
"Absolutely Tender Poached Chicken with 2 Kinds of Sauce" - Recipe ID: 1085284. This is a related recipe to this one. It's so tender, I highly recommend it.
"Basil Sauce Pesto Genovese" - Recipe ID: 931522 that I included with the Step 15 recipe also goes well with this pork!
Story Behind this Recipe
I wanted to make an easy roast pork without using the oven....
The reason the pork is added to the hot water 5 minutes after the heat is turned off in Step 9 is that we want to cook it in 80°C hot water. The 5 minute figure may differ depending on the pot you're using and the ambient temperature, so please adjust accordingly. Just as a reference, in a 25°C room it took 10 minutes for the water to cool down to 80°C. When cooking the pork, you just want to maintain the water temperature, so be sure to only use low heat!