Place cornstarch in one shallow bowl, and beaten eggs in another. Dip cubed chicken with egg, then coat with cornstarch.
Brown all sides of chicken in oil in a non stick skillet over medium high heat. You do not need to cook completely, just brown. Spread browned chicken pieces in a 9x13" pan that has been sprayed with non stick cooking spray.
Preheat oven to 350 degrees.
Combine all of the sauce ingredients in a medium saucepan bring to a boil, whisking often.
Pour sauce over chicken pieces, stirring to coat evenly.
Bake at 350° for about an hour, turning chicken every 20 minutes or so. Sauce should be thickened and bubbly and chicken should be cooked through.