Heat oil in non-stick skillet over medium-high heat.
Toss chicken with Lemon and Pepper and garlic powder to evenly coat.
Add to skillet and cook 4-5 minutes or until thoroughly cooked, stirring frequently.
Remove from heat. DO NOT drain off oil.
In a small bowl, combine vinegar, mustard and Worcestershire sauce with a whisk.
Stir into chicken mixture.
In a large bowl, toss lettuce with chicken mixture, croutons and cheese.
Top with fresh grated Parmesan cheese if desired.