Preheat grill to medium. Grill steaks on rack, uncovered, turning once. Cook 8 to 12 minutes or until the internal temperature reaches 135°F on a meat thermomete for medium-rare doneness.
Meanwhile, for flavored butter, stir together Gorgonzola or blue cheese, cream cheese, butter and nuts. Shape into 1-inch-diameter log. Wrap in plastic wrap, and chill. Cut flavored butter into 8 slices.
Place 1 to 2 slices of flavored butter on each steak. Sprinkle with basil or parsley, if desired.
Note: If you have any leftover flavored butter, use it as a spread on French bread, on toasted pieces of Italian bread topped with slices of Roma tomatoes, on baked potatoes or in mashed potatoes.