Several hours before you plan to roast the meat, grind the caraway, coriander, peppercorns, and salt together. Then blend with the garlic and vinegar until it comes into a paste. Set aside.

Butterfly the pork loin,and spread with the spice mixture. Roll the meat, and fasten in a compact rolled roast. Take any spice blend that has oozed out and rub it into the outside of the roast.

Cover and refrigerate several hours, to marinate.

Roast in a preheated 325 oven for half an hour per pound, until it reaches an internal temperature of 145.

Remove from the oven, and let rest 10 minutes before removing ties and slicing.