Whisk together ketchup, soy sauce, sugar, vinegar, and cornstarch.
Pour 2 teaspoons oil in a frying pan and heat over medium-high heat. Saute chicken 5 to 6 minutes. Take chicken out of pan and set aside.
Pour 1 teaspoon oil in the pan and saute ginger and carrots 2 minutes or until carrots are tender. Mix in snow peas, almonds, water chestnuts, pineapples, and chicken. Cook 3 to 4 minutes, stirring occasionally. Stir in the ketchup mixture and let boil; cook 1 minute.