Whisk the eggs in a bowl. Place flour in a separate bowl. Place cornstarch in a separate bowl.
Season the chicken pieces with salt and pepper. Toss 1/2 cup of chicken pieces, at a time, into the egg, then toss in the flour, then the cornstarch. Repeat with all chicken pieces until all are coated.
Heat the oil in a large non-stick skillet, over medium-high heat. Add coated chicken to skillet. Cook and stir until thoroughly cooked, browned and crispy; about 12 minutes. Remove chicken from skillet and place in a bowl. Tent with foil and set aside.
For the Sauce: In a large sauce pan, combine garlic, red pepper flakes, sugar, water, sweet chili sauce and salt. Bring to a boil, whisking constantly. In a small bowl stir together the cold water and corn starch. When sauce comes to a boil, add the corn starch slurry to the sauce. Stir constantly until sauce thickens. Reduce heat to low.
In the same skillet you cooked chicken in (no need to clean) add the bell pepper, onion and pineapple. Cook over medium heat for a few minutes, or until onions start to soften. Add the sauce and chicken to this skillet. Cook and stir until chicken is reheated.
Serve chicken with rice or noodles!