Preheat the oven to 425
Toss the chopped garlic, chopped fresh Rosemary, salt, pepper and 2 tbs olive oil together in a small bowl.
Rub mixture on the pork loin and place in a zip lock bag and allow to marinate in the refrigerator x 1 hour – up to 24 hours.
When ready to cook, spread the whole fresh rosemary sprigs in the bottom of an oven safe large baking dish.
Remove tenderloin from the zip lock bag and wrap with the four slices of bacon so that the bacon slices begin and end on the bottom side of the tenderloin (to secure bacon in place)
Lay the tenderloin on top of the rosemary sprigs and then place the halved garlic beside the tenderloin (as close a possible) in the baking dish.
Drizzle everything with the remaining 2 tbs of olive oil and any remaining contents of the marinating bag.
Roast in the oven at 425 until an instant read thermometer reads 145. This will depend on the size of the pork loin and the temperature the pork loin began at. So- start checking at about 25 minutes (remove roast from the oven, insert thermometer in the thickest part of the roast – allow to read. Replace into the oven if needed and check again in about 5-10 minutes. Do not allow roast to go over 145 or will start to be dry, stringy and chewy).
When roast has come to the correct temperature, remove from the oven and allow it to rest for 10 minutes – that means, don’t do anything to it for 10 minutes. This allows time for the juices to go back into the meat so that it will be juicy and tender.