Drain pineapple, reserving the juice; set pineapple aside. In a small bowl, combine cornstarch and reserved juice until smooth. Stir in the vinegar, ketchup, brown sugar, soy sauce and ginger; set aside.
In a wok or large skillet, stir-fry the chicken in 2 tablespoons oil for 5-6 minutes or until no longer pink; sprinkle with garlic salt. Remove and keep warm.
Stir-fry the carrots in remaining oil for 4 minutes. Add green pepper; cook and stir until vegetables are crisp-tender. Add chicken and pineapple.
Stir pineapple juice mixture; pour into pan. Bring to a boil; cook and stir for 1-2 minutes or until thickened. Add the tomato wedges. Serve with rice.