MICROWAVE DIRECTIONS: Pierce potatoes with fork; place on microwave-safepaper towel or roasting rack in microwave. Microwave on HIGH for 10 to15 minutes or until tender, turning once halfway through cooking. Cover; let stand 5 minutes.
Meanwhile, heat oil in medium nonstick saucepan over medium-high heat until hot. Add zucchini and bell pepper; cook and stir until zucchini is crisp-tender. Stir in flour, garlic powder and pepper. Add milk; stir until well blended. Cook and stir until thickened and bubbly. Stir in cheese and chicken; cook until thoroughly heated.
To serve, cut potatoes in half lengthwise, cutting to but not through bottom of potatoes. Mash slightly with fork. Spoon chicken mixture over potatoes.