Preheat oven to 300°F. Place beef in a pan, add au jus packet and water to cover. Cover with foil and roast for 4 hours.
While meat roasts, add cabbage, mixed veggies, limas, and corn to a large pot with water. Cook on low.
Stir in both cans of tomatoes and the tomato paste into the veggie pot.
Shred the cooked beef with a fork and add it, along with the roasting broth, to the soup pot.
Add Better Than Bouillon, chives, salt, and pepper to taste.
Add extra water or tomatoes if desired and simmer for 30 minutes.