Set the cooking function at low temperature of the blast chiller and preheat it to 75ºC. Brown the pork fillet in the pan with a drizzle of oil on all sides, salt and pepper. Spread the tamarind jam around the fillet and vacuum-seal it with the chopped onion and the prunes cut in half.
Cook the fillet in the Freddy at 75ºC until it reaches 60ºC to the heart and, once reached, continue cooking for an hour. Once cooked, open the vacuum bag, thicken the cooking liquid in the pan together with the onion and plums, cut the fillet into medallions and serve with the sauce.