To prepare the ice cream custard base, combine milk, egg yolks, 1 cup heavy cream, sugar, salt and lemon zest in a heavy-bottomed sauce pot and whisk thoroughly to combine, making sure the yolks are well integrated. Over medium heat, warm the mixture, whisking steadily, until it thickens—it should coat the back of a wooden spoon when ready. Don’t let it boil, but don’t panic if you get a few lumps. Remove the mixture from heat and stir in the remaining cream and lemon juice. Allow to cool slightly.
Place basil in a mixing bowl and using the back of a wooden spoon, lightly bruise the leaves just to release the oils. Pour the cream mixture over the basil. For great “scoopability” and to add lightness, add 1 tablespoon gin. Cover mixture and place in the refrigerator overnight (or up to 24 hours). Taste from time to time to check the strength of flavor. Remember that freezing the ice cream will dull the flavors a bit.
Strain the mixture through a fine sieve and press lightly on the basil leaves. (Your base might turn faintly green from the chlorophyll!)
Prepare in an ice cream machine according to manufacturer’s instructions. Remove to a freezer-proof container with a lid. Freeze several hours or overnight to harden before serving. Makes about 1 quart.
Note: If you do not have a machine, pour base in a freezer-safe container and freeze. Every 30 minutes, remove and stir vigorously, re-freeze and repeat, until it resembles soft-serve ice cream. Then let it freeze completely.
Co-owner Kate O’Donnell, bywater, Warren