Place brisket, fat side up, in a roasting pan. Sprinkle evenly with garlic salt and pepper. Stir together sauerkraut, preserves, and chili sauce; pour over beef.
Bake, covered, at 350º for 3 1/2 hours or until tender.
Remove brisket from pan, reserving sauce mixture in pan; let stand 20 minutes. Cut brisket across the grain into thin slices using a sharp knife.
Pour sauce mixture from roasting pan through a wire-mesh strainer into a bowl; reserve, if desired. Serve strained sauce and, if desired, sauerkraut with sliced brisket.
To make ahead: Prepare and bake as directed. Remove brisket from pan, reserving sauce mixture in pan; let stand 1 hour. Cut brisket across the grain into thin slices using a sharp knife. Place brisket slices in a 13- x 9-inch baking dish. Pour sauce mixture through a wire-mesh strainer into a bowl, reserving sauerkraut mixture, if desired. Pour strained sauce over brisket slices; cover and chill up to 24 hours. Reheat as directed.
To freeze up to 3 months: Place brisket slices and strained sauce evenly into large zip-top plastic freezer bags; freeze. Thaw in refrigerator overnight. Place brisket and sauce in a 13- x 9-inch baking dish. Reheat as directed.
To reheat: Let stand at room temperature 30 minutes. Bake, covered, at 325° for 45 minutes or until hot.