Thoroughly clean the pork tenderloins with water, and marinate with a sprinkle of salt, demerara sugar and rosemary for 20 minutes.
Dry and brush the tenderloins with oil and mustard. Wrap in foil and refrigerate overnight.
Bake in the oven at 160° for 18-20 minutes and cool.
To make the apricot sauce, gently heat the olive oil, apricot jam, mustard, garlic paste, apple vinegar and stock together in a pan until smooth.
Brown the outside of the pork tenderloins in a frying pan and glaze with the apricot sauce.
Cover in chopped hazelnuts and then bake at 170° for 2 minutes.
For pork jus boil the stock cubes in water, then strain and filter.
Serve 2 pork medallions, garnish with more apricot sauce and the pork jus.