Mix 2 tbsp. sugar and ground cloves on a small plate. Rub one lemon chunk around the rims of two cocktail glasses. Turn rims in the clove sugar.
Cut orange into two slices about 1/4 in. thick; cut slices in half. Put lemon chunks, orange slices, and 3 tbsp. sugar in a cocktail shaker. Using a wooden spoon, muddle together the fruit and sugar until fruit is broken up.
Add about 1 cup ice and whiskey to cocktail shaker. With lid securely fastened, shake vigorously to blend, then strain into the sugared glasses. Garnish each with a whole clove.