To slice or to shred? That's always the debate with beef Brisket. This recipe is slow cooked with onions and herbs to yield a flavorful sauce, no matter how you slice (or shred) it.
Combine ketchup and flour in medium bowl; whisk until well blended. Add onions, brown sugar, vinegar, basil, garlic salt, thyme and pepper; mix well. Place brisket, fat-side up in 3-1/2 to 5-1/2-quart slow cooker. Pour ketchup mixture over brisket. Cover and cook on HIGH 4 hours for sliceable brisket; 6 hours for shredded brisket. Serve with sauce.