"Brushing the bones with tomato paste then browning in the oven firstly then combined with the slow cooking crockpot method will produce the most flavorful richest beef broth --- I usually prepare the ingredients early in the morning, by late evening you will have a wonderful rich beef broth, or you may cook overnight --- the stock may be frozen after cooling, if you don't have a crock pot you may certainly simmer this over very low heat on top of the stove, it will still be delicious! The more bones you use the richer your stock will be, so use lots!..."