First, slice the sirloin steak into thick slices. Then, add them to the crockpot.
Mix together the beef broth, soy sauce, brown sugar and cornstarch together. Add the sliced vegetables to the crockpot then pour the sauce over everything.
Place on high for 4 hours or low for 6 hours. When finished, give it a good stir. Serve over a bed of rice or noodles, enjoy.