Place beef in large resealable bag. Add corn starch; close bag tightly and shake to coat beef. Heat oil in Instant Pot on SAUTÉ setting. Add beef to pot; cook and stir 3 minutes. Remove beef from pot. Add water; stirring with whisk to remove browned bits from bottom of pot. Stir in brown sugar, soy sauce and Seasoning Mix until well blended. Return beef to pot. Close lid. Set Valve to Seal.