Heat oil in large ovenproof nonstick skillet on medium heat. Add zucchini; cook and stir 2 minutes. Add tomato, minced onion, garlic powder, seasoned salt, thyme leaves and pepper; cook and stir 1 minute. Reduce heat to medium-low.
Beat eggs and milk in medium bowl with wire whisk until well blended. Pour over vegetables in skillet. Cover and cook without stirring 5 to 7 minutes or until eggs are just set on bottom.
Sprinkle with cheese. Cover and cook 2 minutes longer or until cheese is melted.