Green peppercorns can be found packed in brine in the specialty foods section of most large supermarkets.
Preheat broiler. Combine first 5 ingredients in small bowl. Season with salt and pepper and mix well. Form mixture into two 3-inch-thick patties on broiler proof pan. Broil 3 minutes. Turn patties over and broil second sides until beef is cooked to desired doneness, about three minutes longer for medium-rare. Top patties with blue cheese. Broil patties until cheese is bubbly, approximately 1 minute.