Preheat your oven to 350 degrees.
In a large skillet, cook the bacon strips until crisp. Drain on a paper towel, then crumble & set aside. Discard some of the bacon grease leaving about 3-4 tablespoons worth of bacon grease in the pan. Saute the onion & celery in the grease for 5 minutes. Add the pears & cook for another 5 minutes. Stir in the minced garlic & rosemary; salt & pepper to taste. Remove from the heat.
In a large bowl, combine the toasted sourdough bread cubes, crumbled bacon, & the pear/onion mixture. Mix in the chicken broth. Season the inside of the butterflied pork roast with salt & pepper. Spread half of the mixture on the inside of the butterflied pork roast, leaving a 1" rim around the edge uncoated. Starting from the long side, roll the pork loin up. Use cooking twine to secure.
Place the pork roast in a large baking dish or roasting pan. Sprinkle the top of the pork roast with your favorite bbq seasoning if desired. Spread the remaining stuffing around the pork roast. Cover with aluminum foil & bake for 1 hour. Remove the foil & cook for an additional 30 minutes or until a thermometer inserted into the pork reaches 145 degrees.