This year, we had a huge box of some of the gnarliest looking bones including marrow bones and knuckles.
First, I took half the bones and roasted them on rimmed baking sheets at 425 for 35-40 minutes.
Then I divided them between two crock pots with water, onion, carrot, celery, wine, garlic.
I let the bones simmer for 12-18 hours on low.
After everything cooled for a little while in the crock pot on the counter, I strained the broth from both crock pots through a wire mesh strainer into various pitchers, and threw out the leftover bones and meat scarps.
Then I let these pitchers of broth sit on the counter until they were around room temp.
Then I transferred them to the fridge to cool down all the way.
When all was said and done, I used the four cups of broth I saved to make French onion soup, my favorite soup, for the first time!