Dissolve 1 package lemon gelatin in 3/4 cup boiling water. Add 2 teaspoons grated onion and 1 teaspoon prepared horseradish. Chill. Fold in 16 ounce jar Harvard beets (Blue Boy) undrained and 3/4 cup diced celery. Pour into mold and chill until firm. Can decorate with sour cream.