• 1 sugar cube
• Dash Angostura bitters
• 1 tsp Cognac or Grand Marnier (optional)
• Champagne or sparkling wine

Place sugar cube in a Champagne flute and dot it with a dash of bitters. If you like, add a splash of Cognac or liqueur to the glass. Top with bubble. Do not stir: the idea is to let the sweet and bitter flavours slowly infuse the drink. Serves 1.