1Heat oil in 12-inch nonstick skillet over medium-high heat. Add mushrooms, onion and frozen vegetables. Sprinkle with contents of seasoning packet from frozen vegetables; stir to coat vegetables. Cook 6 minutes, stirring constantly.
2Make 4 indentations in vegetable mixture. Break 1 egg into each indentation; reduce heat to medium-low. Cover and cook 6 to 9 minutes or until egg whites and yolks are firm, not runny.
3Sprinkle with cheese. Cover and cook about 1 minute or until cheese is melted.