1. Place brisket and contents of spice packet in a Dutch oven; cover with water. Bring to a boil. Reduce heat; cover and simmer for 2-1/2 hours or until meat is tender.
2. Place cabbage and potatoes in a steamer basket; place in a large saucepan over 1 in. of water. Bring to a boil; cover and steam for 25-30 minutes or until tender, adding more water to pan if necessary.
3. Transfer the brisket to a broiler pan. Combine glaze ingredients; brush over beef. Broil 4-6 in. from the heat for 3-4 minutes or until beef is glazed. Thinly slice across the grain.
4. In a small microwave-safe bowl, combine the sauce ingredients. Cover and microwave on high for 30-45 seconds or until butter is melted. Drizzle over cabbage and potatoes. Yield: 6-8 servings.