Preheat the oven to 425°F. Place the pork or sausage meat in a skillet set over medium heat. Cook and stir until crumbly and cooked through. Add the onion and celery and cook until tender, about 4 minutes. Place this mixture in a bowl, add the bread, herbs, paprika and ¾ stock, and toss to combine.
Place the chicken in a roasting pan. Loosely place stuffing in the main cavity and the cavity behind the flap of skin at the neck end. Fold the wings under the body. Loosely tie the legs together. Put some more stuffing at the point where the legs meet. (See Note
for what to do with leftover stuffing.) Brush chicken
with the 2 tsp. oil; season with salt and pepper.
Roast chicken 20 minutes, and then reduce oven to 325°F. Roast 1 hour 25 minutes more, basting occasionally, or until the temperature in the deepest part of a chicken thigh registers 185°F on an instant read thermometer.
Transfer chicken to plate, tent with foil and rest 10 minutes. Meanwhile, make gravy by removing excess fat from pan-drippings. Set pan over medium-high heat. Add stock/flour mixture and bring to a simmer, scraping the pan to dislodge any brown bits on the bottom. Simmer gravy a few minutes, until thickened, and then season with salt and pepper.
Remove stuffing from the bird and set it in a bowl (if not piping hot, heat through in the oven a few minutes). Carve the chicken and serve with the stuffing and gravy.
: After stuffing the chicken, place any leftover stuffing in a lightly buttered baking dish. Cover and bake alongside the chicken 20 minutes. Uncover and bake 10 minutes more, or until hot.