Whisk the mayo, ketchup, red wine vinegar, onion, parsley, tarragon and Worcestershire sauce until blended. Refrigerate until ready to use.
Cook the bacon until crisp.
Light a grill and fill a large bowl with ice water. Gently mix the ground chuck with the ground sirloin, salt and pepper. Form the meat into patties and submerge in the cold water and let soak for 30 seconds. Immediately transfer the burgers to the grill and brush with some of the melted butter. Grill over high heat for 9 minutes for medium-rare meat, turning once or twice and brushing occasionally with butter. Top the burgers with the cheese during the last-minute of grilling and let melt.
Spread the Russian dressing on the buns. Set the lettuce leaves and tomato slices on the bottom halves and top with the burgers, red onion and bacon.