In a large skillet, heat oil over medium-high heat. Add potatoes and onion; cook and stir 4-6 minutes or until potatoes are crisp-tender. Stir in zucchini and sausage; cook 4-6 minutes longer or until the vegetables are tender., Gently stir in red peppers, tomatoes, salt and pepper; sprinkle with cheese. With back of spoon, make four wells in potato mixture; break an egg into each well. Reduce heat to medium. Cook, covered, 4-6 minutes or until egg whites are completely set and yolks begin to thicken but are not hard.