Preheat the oven to 325°F.

Dice half of the onion into 1/2-inch pieces and slice the other half thinly for the roasting pan.

Fry the bacon in a large skillet until crisp, then move it to a plate and keep the bacon grease in the pan.

Add poultry seasoning, diced onion, and celery to the pan. Cook for about 8 minutes, stirring, until tender but not browned.

Butterfly the pork loin lengthwise but do not cut all the way through. Open it like a book and pound it to about 3/4 inch thick.

Mix the cooked vegetables with the bread cubes, add broth gradually until just moist, crumble in bacon, add cranberries, and season with salt and pepper. Let cool before using.

Spread the stuffing over the pork, roll it up jelly-roll style, and tie with kitchen twine every 1.5 inches.

Rub the outside of the roast with olive oil and season with garlic powder, sage, rosemary, salt, and black pepper.

Place the rolled pork seam-side down in a roasting pan, scatter the sliced onion around, pour in chicken broth until it is about 1/2 inch deep. Roast for 90 to 110 minutes until a thermometer reads 140°F in the center.

Let the roast rest for 15 minutes before slicing. Remove twine and slice into rounds, spooning pan juices over the top before serving.