If I am making prime rib on a rotisserie then how is the tastiest way to make the au jus?

I would skip the au jus and make a horseradish sauce. Mix sour cream with some lemon juice, salt, pepper, and a few tablespoons of prepared horseradish (drained) to taste!

I would cut the bones off and ask your butcher for some extra fatback to tie on. Arrange a pan to catch the drippings. Add low sodium broth to increase the volume if you need to. Cook the rob bones on the side and have the next day with BBQ sauce.

Start with some olive oil and butter add shallots garlic fresh thyme and rosemary salt pepper little flour cook for a few minutes add beef stock simmer for fifteen minutes