Preheat oven broiler. Adjust oven rack to the second highest position.
Open rye and place on cookie sheet or jellyroll pan. Mix the last three ingredients in a small bowl. Put about one rounded teaspoon of mixture on each rye slice and spread to the edges. Usually takes about a loaf.
Place under broiler for about one minute. Watch carefully as it will brown very quickly. You just want it to bubble up.