YIELD: Makes about 1 quart
INGREDIENTS
1 2/3 cups heavy cream
2 teaspoons fennel seeds, crushed
1 large lemon - zest only
1 cup whole milk
3/4 cup sugar, divided
4 large egg yolks
PREPARATION
Bring cream and fennel seeds just to a simmer in a small heavy saucepan, add the lemon zest, then cover and let steep about 30 minutes.
Whisk together yolks and remaining 1/4 cup sugar in a large bowl.
Bring milk, 1/2 cup sugar, and a pinch of salt to a simmer in a heavy medium saucepan over medium heat, stirring.
Add milk mixture in a slow stream, whisking. Strain fennel cream through fine-mesh sieve into the milk-egg mix, pressing on solids.
Heat mixture on a bain marie and cook, stirring continuously with a wooden spoon, until mixture coats back of spoon and registers 175°F on an instant-read thermometer (do not let boil).
Strain custard through a fine-mesh sieve into a metal bowl, cover with plastic wrap, and chill overnight.
Churn in ice cream maker for 15 minutes. Transfer to an airtight container and put in freezer to harden, about 2 hours.