It's about a poor wandering boy that's hungry who winds up at this ugly old woman's house and asks for food but she only has these different types of vegetables and other thing. They decide to make a soup and they begin to put different things from vegetables to a dogs chewed up bone

I read a similar book called Stone Soup (stoned soup-can't remember 100%). Don't remember the part about a dog bone, but try that book as it sounds very familiar to what you are talking about.