Prep time: 15 mins.
Cook time: 15 mins.
In large nonstick fry pan over medium heat, melt the margarine. Saute onion with sugar until tender and golden brown, about 4 mins. Add the mushrooms and vinegar and cook till mushrooms are tender, 3 mins. Transfer the onion and mushroom mix to a small bowl. In a large bowl, combine the egg whites, milk, salt and pepper. Beat egg-white mixture until stiff peaks form. Wipe out nonstick fry pan and coat with nonstick cooking spray. Place over medium heat. Add the egg-white mix and gently level using back of spoon.
Additional notes: All the fat and cholesterol in eggs reside in the yolks, while the egg whites are rich in protein and albumin. For healthier cooking of any recipe with eggs, substitute 2 egg whites for each whole egg.