Liver and Onions

1 pound calves liver, approximately 3/8 inch thick
1 Tablespoon butter
1 large yellow onion, sliced thin
2 teaspoons lemon juice
1 teaspoon Worcestershire sauce
2 Tablespoons minced parsley for garnish
salt and pepper to taste

1. Cut the liver into thin strips. 
2. In a large nonstick skilled, melt the butter over medium high heat.  Add the onion and cook until tender, stirring frequently.
3. Add the liver.  Salt and pepper as desired.  Cook over medium high heat for 3 to 4 minutes or until tender, stirring frequently.  Transfer to a plate.
4. Stir the lemon juice and the Worcestershire sauce into the drippings in the skillet, stirring to loosen any bits that may be stuck to the pan.  Pour over liver.
5. Garnish with parsley.