Combine 1 1/2 cups of water, reserved pineapple juice, sugar, vinegar, and orange food coloring in a medium saucepan. Bring to a boil over medium heat; set aside.
Mix 1/4 cup cornstarch and 1/4 cup water together in a small bowl until smooth; pour into the sauce, stirring continuously, until slightly thickened.
Place flour, 2 tablespoons oil, 2 tablespoons cornstarch, egg, salt, and white pepper in a large bowl; gradually whisk in 1 1/2 cups water to make a thick batter.
Add chicken pieces; stir until well coated.
Heat oil in a large, deep skillet or wok to 360 degrees F (180 degrees C). Fry chicken pieces in preheated oil until golden, about 10 minutes; remove and drain on paper towels.
Layer green peppers, pineapple chunks, and cooked chicken pieces on a platter; pour hot sweet and sour sauce over top.
Serve hot and enjoy!
Editor's Note
We have determined the nutritional value of oil for frying based on a retention value of 10% after cooking. The exact amount may vary depending on cook time and temperature, ingredient density, and the specific type of oil used.