Step 1In a saucepan over low heat, bring the milk, whipping cream and lemon verbena leaves to a full simmer. Remove the mixture from the heat, pour into a glass bowl and let cool to room temperature. Cover and refrigerate overnight.
Step 2The next day, strain the milk-cream mixture into a saucepan (discarding the lemon verbena leaves) and heat to a simmer.
Step 3In the bowl of an electric mixer, beat together the egg yolks and sugar until thick and lemon colored, about 1 minute.
Step 4Pour a third of the hot milk-cream mixture into the egg yolk mixture and stir to blend, then pour the entire mixture back into the saucepan.
Step 5Heat and stir over medium heat until the custard begins to thicken and just begins to bubble around the edge, about 3 minutes.
Step 6Remove the custard from the heat and pour it into a metal bowl. Set the bowl in a larger bowl filled with ice water. Let the mixture stand, stirring occasionally, until the custard is chilled. Whisk in the lemon juice.
Step 7Freeze in an ice cream maker according to the manufacturer's directions. Spoon the ice cream into a chilled glass bowl or loaf dish and freeze until ready to serve.