Fill a highball glass with ice cubes.
Add 30ml brandy, 30ml gin, and 30ml sweet vermouth.
Top with 90ml carbonated water (or ginger ale for a sweeter, spicier variation).
Express a lemon peel twist over the glass to release its oils, then drop it in or drape it on the rim.
Give a brief, gentle stir to integrate and serve immediately.
Expressing the lemon peel rather than simply dropping it in is key - the burst of citrus oils sits on the surface of the drink and perfumes every sip. A brief, gentle stir after topping preserves the carbonation while ensuring the spirits and vermouth are properly integrated.
My Bar Shelf reads your shelf and shows you every cocktail you can make from what you already own, including English Highball.