1. Place 1/2 of the brisket in slow cooker. Add onion.
2. Mix Seasoning, beer, chili sauce and brown sugar until blended. Pour 1/2 of the mixture over brisket. Top with remaining brisket and seasoning mixture. Cover.
3. Cook 8 hours on LOW or 4 hours on HIGH.
4. Remove brisket to serving platter. Slice thinly across the grain. Stir sauce before serving. Serve with brisket.
Slow Cooker Tip: For best results, do not remove cover during cooking.