Marinade pork loin with dry herbs (thyme) salt pepper and fresh rosemary for as long as you can. 

Seared both side of pork till brown and pour some balsamic vinegar over pork loin (still in the pan) after you get some nice color on pork loin, remove and heat it in the oven at 200C for about 25-30 mins. continue heating in oven (with potatoes by the side) and drizzle lotsa balsamic vinegar over potatoes and pork. 

After heating let pork rest for a while before serving.