Pre-heat the ove to 425 F (210C).
Separetly toss the parsnips and the aples in the begetable oil and spread out on two large rimmed baking sheets. Cook for 12-20 minutes, checking every five minutes and stirring as the pieces brown, remove from the oven and transfer to a large bowl.
Cook the sausage in a very large frying pan over medium-high heat, breaking the meat into pieces with a spoon. Cook about 15 minutes. Use a slotted spoon, add to the parsnips and apples.
Add the onions and celery to the fry pan and cook until translucent, but not brownned. Add the butter, sage and stock. Heat until the butter melts, then add the parsnips and apple mixture. STir in the bred and season with salt and pepper.
Butter two 9x13" baking dishes. Cover with foil. The dish can be made up to this point and kept for one day. Cover and place in fridge.
When ready - pre-heat the over to 350F, bake stuffing covered until heated through, about one hour. Uncover and bake until the top begins to brown, about 10 minutes.
Makes 12 servings.
This stuffing recipe comes from our good friend, Margot Arbogast.