Wash the chicken or fowl and rub the interior with lemon juice.
Heat the butter and oil in a 12-inch skillet, add the onions, and sauté lightly.
Add the ground pork or sausage meat, break it up with a fork, mix with the onions, and cook 2 to 3 minutes.
Add the parsley, seasonings, and breadcrumbs and blend well.
Transfer to a bowl, add the eggs, and mix thoroughly with the hands or with a large spoon. Correct the seasoning.
Stuff the chicken, not too firmly. Place a triple-thick square of foil over the stuffing, close the vent, and sew so that the liquid in the pan will not seep into the stuffing. You may want to stuff the neck cavity as well. If so, secure the neck skin firmly to the chicken's halfway.
Poach, allowing about 30 minutes of simmering per pound.
When the fowl is tender, transfer to a hot platter.
Prepare cream or velouté sauce, using the poaching broth.
Serve the stuffed chicken with noodles or creamy mashed potatoes. A spinach soufflé or spinach ring filled with tiny buttered carrots would be a pleasant accompaniment. For an excellent contrast, also serve a sharp pickle or pickled peaches.