Trim excess fat from pork; cut into 1 inch cubes and set aside. Thoroughly combine cornstarch, teriyaki sauce and sesame seed in medium bowl (mixture will be very stiff).
Stir in pork cubes; let stand 30 minutes. Meanwhile, prepare Sweet & Sour Sauce; (see below) keep warm. Heat oil in medium saucepan over medium-high heat to 300F.
Add 1/3 of the pork cubes and cook, stirring constantly, until golden brown, about 2 minutes. Remove and drain on paper towels.
Repeat with remaining pork. Serve immediately with warm Sweet & Sour Sauce.
SWEET & SOUR SAUCE: Combine sugar, vinegar, catsup, water, teriyaki sauce and cornstarch in small saucepan. Cook over high heat, stirring constantly, until thickened. Typed by Syd Bigger.