A lush, nutty sour that balances sweet almond-flavoured amaretto with bright lemon juice. Chef Jeffrey Morgenthaler's version with egg white gives it a gorgeous, frothy head.

• Amaretto4.5 cl
• Cask-strength bourbon2 cl
• Fresh lemon juice3 cl
• Simple syrup0.75 cl
• Egg white1

1. 1Combine all ingredients in a shaker without ice and dry shake for 10 seconds.
2. 2Add ice and shake vigorously for another 15 seconds.
3. 3Strain into a rocks glass over a large ice cube.
4. 4Garnish with Angostura bitters drops on the foam and a Luxardo cherry.