How to Make It
Combine egg whites and 1 tablespoon cornstarch in a large bowl, stirring with a whisk. Add chicken to bowl; toss to coat.
Combine remaining 1 teaspoon cornstarch, ketchup, and next 4 ingredients (through soy sauce) in a bowl, stirring with a whisk.
Heat a large nonstick skillet over medium-high heat. Add 1 tablespoon oil to pan; swirl to coat. Add bell pepper to pan; cook 2 minutes, stirring frequently. Add pineapple, ginger, and onions to pan; cook 2 minutes, stirring occasionally. Transfer bell pepper mixture to a plate.
Add remaining 1 tablespoon oil to pan. Add chicken mixture, allowing any excess egg white mixture to drip back into bowl. Stir-fry 6 minutes or until chicken is browned and done. Add ketchup mixture and bell pepper mixture to pan. Bring to a simmer; simmer 1 minute or until slightly thickened. Sprinkle with salt; serve immediately.