Add the butter, miso paste and lemon to a bowl and beat together with a fork.
Spoon the butter into the centre of a piece of plastic wrap, roll into a sausage and twist the ends to seal.
Transfer to the refrigerator to chill and firm.
Once firm, cut thin discs of the butter and lay them over the scallops in the shell.
Place the scallops shell down on a hot barbecue or under a grill (broiler) on low heat and cook for 1–2 minutes, or until cooked through.
Transfer to a serving platter and eat straight from the shell.
