This is a soup my mother fixed often when I was a child. It's not easy to find oxtails but the search is definitely worth it. I had a friend once who bought a side of beef and was going to throw away the tail. I snatched them out of her hand and hugging them to my chest, ran home and made oxtail soup. I brought her a bowl and after much hesitation she tried it. That was the last time she gave me these choice bones.