Preheat oven on broiler setting.
Lightly coat a 9x13 baking sheet with nonstick cooking spray
Sprinkle pan lightly with half of the Parmesan cheese.
In a medium bowl mix together mayonnaise, mustard, Worchester, vinegar, onion and lemon juice.
Dip Cod lightly in mayonnaise mixture and place in baking pan.
Sprinkle remaining Parmesan cheese on top of Cod
Bake on broiler setting on lower rack for 10 minutes or until Cod reaches 145 degrees.
Serve with roasted brussels sprouts or other vegetables and brown rice.