I start roasting the veggies & beef bones first. After a while, I smear the crushed tomatoes ont the bones & veggies. A wile later, I dump it all into a big stock pot, bring the stock to a boil, lower the heat & let it simmer for several hours until the meat falls off the bones.
But now, I don't make beef stock that way. I got some beef shanks in the freezer. I just brown the shanks in a little oil, had the veggies & tomatoes with seasonings to the stock for soup & let it boil. This is the much faster way when you don't want to use beef bones.