Coat the cubed chicken in ½ cup of cornstarch, then pour the scrambled eggs over the chicken and mix to coat evenly.
Heat about an inch of oil in a large pan over medium heat. Fry the chicken pieces in batches, about 3 minutes on each side, until golden and cooked through. Remove and set aside.
In a bowl, combine the pineapple juice, brown sugar, soy sauce, minced garlic, and 1 tablespoon of cornstarch. Stir well to dissolve the cornstarch.
In the same pan, add a little oil and sauté the sliced sweet peppers and onions until softened, about 3–4 minutes.
Return the cooked chicken to the pan and pour over the pineapple juice mixture. Add the pineapple tidbits and stir everything together. Let simmer for 2–3 minutes until the sauce thickens.
Serve the pineapple chicken over your favorite rice.