Pre-heat oven to 375 F. Line a baking sheet with parchment paper or a non-stick baking mat. Beat together shortening and granulated sugar until light and fluffy. Beat in egg yolk, orange and lemon peels, and lemon juice. Stir in flour and salt. Chill dough for approximately 1 hour. Form dough into 1" balls, then dip in egg white and roll in chopped hazelnuts. Press half candied cherry into the top of each cookie. Bake for about 8 minutes or until cookies are set but not brown. Allow to cool for 1 minute on baking sheets, then remove to wire racks to cool completely.