Preheat oven to 375 F.

Butterfly roast.

In large skillet over medium-high heat, heat oil and butter. Add celery, carrots and onions; cook until softened, about 5 minutes.

While vegetables are cooking, whisk eggs; milk; salt, to taste; and pepper, to taste, until well combined. Mince sage and rosemary.

In large bowl, combine bread, vegetable mixture, liquid ingredients, apples, sage and rosemary. Gently toss until bread absorbs most of the liquid.

Cut three pieces of butcher’s twine about 4 inches longer than the longest side of butterflied roast. Lay string on cutting board horizontally and lay roast on top of string to cover.

Place half of the stuffing mixture onto butterflied pork loin and press down firmly. Roll roast up and tie with butcher’s twine to hold it together, taking care not to tie too tightly, and press any stuffing that comes loose back into ends of roast.

Place stuffed and tied roast, fat cap up, on rack over baking sheet. Season liberally with salt and pepper; roast until meat thermometer inserted into roast registers 140 F, 75-90 minutes.

Place remaining stuffing in a small ovenproof casserole dish and cover with foil. After roasting 30 minutes, place extra stuffing in oven to cook alongside roast.

Remove foil from extra stuffing and remove roast from oven. Let rest for 10 minutes then remove the extra stuffing from oven.

Cut twine from roast and discard. Cut roast into six thick slices, taking care not to lose stuffing. Serve with extra stuffing and gravy.