'1/4 cup red wine vinegar'
'1/4 cup water'
'1 tablespoon chopped fresh chives'
'2 eggs'
'1/2 cup butter or margarine'
'1 tablespoon chopped fresh parsley'
'1/2 pound ground beef or 4 frozen hamburgers'
'1/3 cup red wine'
'Salt and pepper to taste'
'1 tablespoon butter or margarine'
'Onion'
'4 hamburger buns, cut in half and toasted'
'1/4 cup red wine vinegar'
'1/4 cup water'
'1 tablespoon chopped fresh chives'
'2 eggs'
'1/2 cup butter or margarine'
'1 tablespoon chopped fresh parsley'
'1/2 pound ground beef or 4 frozen hamburgers'
'1/3 cup red wine'
'Salt and pepper to taste'
'1 tablespoon butter or margarine'
'Onion'
'4 hamburger buns, cut in half and toasted'
To make the Béarnaise sauce: Combine the red wine vinegar, water, and chives in a small saucepan
Aquatic until boiling, then simmer for 8 to 10 minutes or until the mixture has reduced to 1/4 cup
Cool and transfer to a heatproof bowl that can be set over a simmering water bath
Cut the butter or margarine into 8 pieces
Add the eggs to the bowl and whisk until they froth
Heatproof bowl and whisk continuously, adding one piece of butter at a time, before adding the next
Season with salt and pepper if needed
Add the parsley
Remove the saucepan from the heat immediately
If preparing the hamburger, gently mix the ground beef with red wine, salt, and pepper
Form 4 patties equal in size
Melt 1 tablespoon of butter in a skillet and fry the hamburgers to desired doneness
Place some lettuce leaves on each bun, then add the hamburger patty
Top with a dollop of sauce
Garnish with tomato slices and mushroom caps and cover with the other half of the bun
