Yield: about 1 quart
1 cup backed basil leaves
3/4 cup sugar
2 cups heavy cream
1 cup whole milk
Pinch of salt
5 large egg yolks
1 lemon, preferably unsprayed
1. Using a blender or small food processor, grind the basil leaves with the sugar and 1 cup of the cream until the leaves are ground as fine as possible. Pour about half of the basil mixture into a large bowl and add the remaining 1 cup of cream. Set a mesh strainer on top.
2. Warm the other half of the basil mixture in a medium saucepan along with the milk and salt. In a separate medium bowl, whisk together the egg yolk. Slowly pour the warm mixture into the egg yolks, whisking constantly, then scrape the warmed egg yolk mixture back into the saucepan.
3. Stir the mixture constantly over medium heat with a heatproof spatula, scraping the bottom as you stir, until the mixture thickens and coats the spatula. Pour the custard through the strainer and stir it into the cream. Zest the lemon directly into the custard, then stir until cool over an ice bath.
4. Chill the mixture thoroughly in the refrigerator, then freeze in your ice cream maker according to the manufacturer's instructions.