Turn crockpot to High. In bottom of crockpot, add in beef broth, stew meat, onion soup mix, and boullion cubes. If you have time in your day, save the potatoes and carrotts for addition later in the day. If not, put the potatoes and the carrots on top of the stew meat.
Cover pot and leave alone to cook for a good 8-10 hours or so. If you were able to stagger the meat and veggies, add the veggies to the meat and broth mixture about 4 hours into cook time.
About 15-30 minutes before serving, add your slurry mixture into stew and allow 15-30 minutes to thicken the broth.
Serve with warm, crusty bread to dip into your yummy gravy....ENJOY! :)