You will need:

1 pound boneless skinless chicken thighs cut into 1-inch pieces, or chicken breasts
1 teaspoon salt
1/ 2 cup cornstarch
1 1/ 2 cups flour
1 egg, beaten
1 tablespoon oil
1 1 /4 cups water
Vegetable oil, for frying
1 red bell pepper, cut into 1” pieces
1 green bell pepper, cut into 1” pieces
1 medium yellow onion, cut into 1” pieces
1 tablespoon oil
1 cup pineapple chunks

Sweet and Sour Sauce
1/ 2 cup sugar
1/ 4 cup white vinegar
2 teaspoon garlic, minced, or garlic powder
2 tablespoons soy sauce
1/ 4 cup ketchup
2 tablespoons cornstarch, mixed with 2 tablespoons water

Method:

In a large bowl, mix together the cornstarch, flour and salt. Add the egg, 1 tablespoon oil and water, whisking until smooth. (The consistency should be thick like pancake batter.) Add the cubed chicken pieces to the batter and coat thoroughly. Let it marinate for 10 minutes at room temperature or up to one hour in the fridge. Add one inch of oil to a medium saucepan or deep fryer and heat to 350˚F. Set aside a wire rack and slotted spoon or mesh strainer. Add the chicken to the hot oil in batches, frying for 3-4 minutes until golden and crispy. Remove to the rack with a slotted spoon and repeat for remaining chicken. Place a skillet or wok over medium-high heat. Add the 1 tablespoon oil, onion and bell peppers and sauté for 2-4 minutes until slightly softened. Add the pineapple to the pan followed by the sauce ingredients: garlic, sugar, vinegar, soy sauce and ketchup. Bring to a simmer and give it a taste test, adding sugar and vinegar to get the balance to your liking. Mix the cornstarch and water together in a cup. Then slowly stir it into the pan. Reduce heat slightly and simmer for 2-3 minutes or until the sauce is thick enough to coat the vegetables. Add the cooked chicken back to the pan and stir to coat evenly. Remove the skillet from heat (the sauce will thicken further and become sticky). Serve immediately.