In a large pot, place beef tongue, beef heart, 2 peeled and sliced onions, celery, and carrots. Cover with water, add 1 tablespoon savory, and 1 teaspoon each theme, salt, pepper, and sage. Bring JUST to a boil, reduce heat to medium, and simmer for 2 hours.
As you wait, rinse the kidneys off, and cut all the meat from the white stuff. Place the kidney meat in a bowl with 1 cup vinegar and 3 cups water. Stir well, let it sit for 20 minutes before draining and rinsing it.
Add kidneys and beef liver to the pot, continue to cook for another hour or so, until the tongue and heart are tender.
Remove everything from the cooking liquid, reserving the liquid for later. Discard vegetables, allow meats to cool until you can handle them.
Use a sharp knife to trim gristle, skin, or “ugly bits” from the heart and tongue. Chop all of the organ meat to ~ 1″ cubes or strips. Run all the meat through the larger grain opening on your meat grinder, mix well. Run through once more, this time with the finer cut attachment.
Grate or finely chop the remaining 3 onions, and grate the suet. Add both to the meat mixture, stir well.
Run your toasted oats through the food processor to break them up a bit, add to the mixture. Stir well
Season the mixture to your liking, the seasonings recommended in the ingredients are the way I like it.
I used the sausage making attachment for my Kitchenaid to stuff the sausage casings, which I’d soaked in hot water for a few minutes to soften. As I haven’t made sausage before… not sure what to recommend if you use something else. Don’t stuff them TOO full, or they run the risk of exploding when simmered.
Once the sausage casings are stuffed, tie them off.
Prick each casing a few times with a fork or JUST the tip of a sharp knife. Place in a large pot of boiling water, turn the heat down and and simmer for about 3 hours.