I have never seen oxtail's except vacuum packed at BJ's.

Not a recipe:

I would brown short ribs in a heavy pan large enough for all the
ingredients. Remove them from the pan and add chopped onions, celery,
carrot (maybe) and fresh button or cremini mushrooms. Saute until softened.
Mix with an appropriate amount of sauerkraut, push the ribs into the
mixture. Add whatever cooking liquid you like. I generally use chicken
stock. Beer works, as does water. Don't drown it.

Cover and low simmer on stove top or in the oven until 'kraut is
softened, and everything melds.

You could add apples, potatoes, your spices of choice, whatever...
Proportions to your taste but my meat to 'kraut mixture ratio would be 1:3,
at the start of cooking. I like a lot of mushrooms.

I have done this with country style pork ribs as well.

--
Dave S