1 1/2 cups whole milk
1 1/2 cups heavy whipping cream
1/4 cup lemon verbena leaves, rinsed, dried and chopped
1/8 teaspoon salt
2 large eggs
6 tablespoons superfine sugar
Grated zest of 1 lemon
1/4 cup freshly squeezed lemon juice
3 tablespoons butter, cut into small chunks
Bring the milk, cream, chopped verbena leaves and salt to a boil in a medium saucepan over medium heat. Remove from heat, cover and let steep for 30 minutes.
While mixture is steeping, whisk eggs with superfine sugar in a 2 1/2-quart saucepan until light. Add grated zest and lemon juice. Whisk briskly by hand over medium-low heat, adding small chunks of butter, one at a time, making sure the butter is melted before each addition. When mixture just begins to bubble, it will be thickened, similar to the consistency of pudding. Remove from heat.
Pour the steeped mixture through a fine strainer into a bowl, pressing on the lemon verbena to extract all the flavorful oils. Discard the lemon verbena.
Gradually pour the milk-cream mixture into the lemon mixture, whisking to blend and incorporate completely before adding more. When all liquid has been blended with lemon mixture, allow to cool to room temperature. Refrigerate, covered, until thoroughly chilled.
Freeze the mixture according to the instructions for your ice cream maker. Makes about 1 quart.