Scrub potatoes with vegetable brush under cold running water. Peel. Cut into 1/2–inch cubes. Place in 3-quart saucepan and add cold water to cover. Over high heat, bring to boiling. Reduce heat to medium-high and cook until potatoes are tender, about 8 to 10 minutes. Drain.
In a large nonstick skillet over medium-high heat, heat 1 tablespoon of the oil. Add mushrooms and cook, stirring occasionally, until browned, about 6 to 7 minutes. Stir in zucchini, bell pepper and garlic and cook until crisp tender, about 4 minutes. Add potatoes and remove from the heat.
Over medium-high heat, heat the remaining 1 ½ teaspoons oil in 10-inch nonstick skillet with oven proof handle* Add the potato mixture and cook 1 minute. In small bowl, combine egg substitute, cheese, and pepper. Pour over vegetables in skillet and stir to combine. Reduce heat to medium and cook until almost set, about 10 minutes. Transfer to the oven and bake until cooked through, about 10 to 12 minutes longer. Remove from the oven and let stand 5 minutes. Cut into wedges to serve.
*To ovenproof handle, wrap with aluminum foil.
Nutritional Analysis per serving: 226 calories, 19 g protein, 22 g carbohydrates, 8 g fat, 2 g saturated fat (30%of calories from fat), 6 mg cholesterol, 2 g fiber, 652 mg sodium.