Piggybacking since I can't see the OP.

There's a recipe from an old Cooking Light for a beef pot rost in the
crock pot that makes the most awesome stock for veggie soup - I altered
it a little bit. Basically you brown a big hunk of cow, toss it in the
crock on top of onions, celery and carrots, then add a cup of white
wine, 2T tomato paste, garlic, 1 bay leaf, fresh parsley, black
pepper, a little thyme, and a cup of chicken broth. Cook on low 10
hours or so (5-6 lb roast), remove the meat, do whatever you want with
it (I make one meal from it and then add some leftover meat to the
soup), and save the broth as a veggie base. It's wonderful.

-L.