1. Cut one clementine into thin wedges.
2. Wet the rim of a cocktail glass with a clementine wedge, then press rim in sugar. 
3. Using a citrus press, juice two clementines. 
4. Place ice cubes, 2 clementine wedges, clementine juice, vodka, white wine, San Pellegrino, and Angostura bitters in a glass. Stir well.
5. Rub rosemary sprig between your hands to release the aroma and place in glass. 

Chef's secret: For a non-alcoholic version, replace vodka and wine by an equal amount of unflavoured sparkling water.