Fill a tall glass with lots of ice and add 50ml vodka, 25ml fresh lemon juice, 10ml gomme*, cover and shake gently. Add more ice and top the glass up with champagne. Gently pour 15ml of cassis over the top and garnish with a lemon wedge and red currents, or whatever pretty items you have in your fruit bowl!
*gomme - fancy industry word for sugar syrup.
Very simply made by mixing the same amounts of water and sugar over a gentle heat until the sugar is completely dissolved. Leave to cool and bottle it – this will last for ages!