Put the the cows' feet into a large bowl and soak in cold water for 1 hour. Drain. Using a large stock pot put the cows' feet into the pot and add water to cover the bones. Boil on medium heat. Add bay leaf, onions garlic, and carrots. Skim off the fat during the cooking process. You may have to add a little water during this process. But you don't want to lose the flavor that is in less water. Use your judgement on this. Cook on medium heat for 2-3 hours. When the meat and gristle is off the bone, it is done.