pinch of salt
2 cups whole milk
1/3 cup sugar
1 cup packed basil leaves
3 large egg yolks
1. Bring milk, sugar, and a pinch of salt just to a boil in a small saucepan, stirring until sugar has dissolved. Remove from heat and stir in basil. Let steep, covered, 30 minutes.
5. Put yolks in a small bowl. Strain milk mixture through a sieve into another bowl, discard basil, and return to saucepan. Whisk about 1/2 cup warm milk mixture into yolks, then whisk into remaining milk in saucepan. Cook over medium-low heat, stirring constantly and registers 170°F on an instant-read thermometer and set aside.
6. Place N2O cartridge in the holder with the small end visible. Pour the custard liquid into the dispenser. Put the dispenser in the fridge to cool it for 1 hour to allow the custard to set.
7. Shake the dispenser 3-6 times and serve.