Heat oil in stockpot over medium heat until hot. Place boneless beef brisket flat half in stockpot; brown evenly.
Combine water, chili garlic sauce, brown sugar and soy sauce. Pour over brisket; bring to a boil. Reduce heat; cover tightly and simmer 2 hours and 45 minutes to 3 hours and 15 minutes, or until brisket is fork-tender.
Remove brisket; keep warm. Skim fat from cooking liquid; bring to a boil. Cook 10 to 12 minutes or until reduced by half.
Trim fat from brisket. Carve diagonally across the grain into thin slices. Serve with sauce. Serve with kimchee if desired.