Marinate pork in Italian dressing, at least 30 minutes, preferably overnight.
Preheat oven to 350 degrees Fahrenheit.
Remove pork from marinade and discard marinade.
Pat dry and season well with salt and pepper.
Heat 2 tbsp butter in a large heavy pan.
Brown pork loin on all sides, about 2 minutes per side.
When pork loin has browned, add to roasting pan or baking sheet.
Wash pears well and cut in half, removing the core. Pat dry.
Arrange around pork loin in pan, and cover with diced shallots.
Generously season pork and pears with herbs, salt, and pepper.
Drizzle butter and herbs over pork and pears. Toss pears lightly to coat in herb butter.
Roast 20-30 minutes, checking temperature after 20 minutes.
When porks internal temperature reaches 140 degrees, remove from oven and let rest 10 minutes before carving.
Serve and enjoy!