In a large stockpot, combine the shredded beef, leftover cooked vegetables (if using), frozen mixed vegetables, and beef broth.
Bring the mixture to a boil over medium-high heat, stirring occasionally. Break up any large pieces of beef with your spoon as it heats.
Once the stew is hot and the vegetables are tender, mix the cornstarch and water in a small bowl until smooth.
Stir the cornstarch mixture into the stew and cook for 2–3 minutes, or until the broth has thickened.
If you prefer a thicker stew, mix an additional tablespoon of cornstarch with a little water and add it gradually until you reach your desired consistency.
Serve hot and enjoy!
