Select a 3 to 4 lb chuck roast, 2 1/2 to 3" thick. Place meat in shallow glass dish; pour California Marinade over meat. Cover dish with plastic wrap. Refrigerate 24 hours, turning meat frequently.
Remove meat from marinade. Stir 2 tbsp. ketchup into marinade; heat through on grill. Brush on meat. Place roast on grill 4" from medium coals.
Cook 1 to 1 1/4 hours or until tender, turning frequently and basting every 5 to 6 minutes with hot marinade. Serve roast rare in the middle and browned on the outside.
6 to 8 servings