Use teaspoon or melon baller to scoop out zucchini flesh, leaving 1/2-inch-thick shells. Place, rounded-sides down, in single layer in microwaveable dish. Microwave on HIGH 4 min. Meanwhile, heat dressing in large skillet on medium-high heat. Add peppers and onions; cook and stir 3 to 5 min. or until crisp-tender. Stir in rice and parsley.