3 ounces bittersweet chocolate, broken into chunks
1/4 cup flour and 1/4 cup confectioners' sugar for rolling
Cream butter and sugar with an electric mixer until light. Add
egg and mix well.
Sift together the flour and cornstarch. Add to creamed mixture
and blend well. Mix in nuts.
Gather dough into a ball and wrap in wax paper. Chill for at
least 4 hours.
Sprinkle a board with 1/4 cup flour and 1/4 cup confectioners'
sugar. Roll the dough out to a 1/4-inch thickness. Cut with
a small heart-shaped cookie cutter about 1 1/2 inch long. Place
cookies on ungreased cookie sheets. Chill cookies on the sheets
briefly while preheating the oven.
Heat oven to 325 degrees F. Bake cookies for 10 to 15 minutes
or until lightly browned.
Cool cookies on a rack while melting chocolate in a heavy-bottomed
small pan or over simmering water in a double boiler.
Dip half of each heart into the melted chocolate and return
to rack to cool.