I created this recipe for my dad as a Father's Day treat because he loves frozen custard, and green is his favorite color. This rich, ultra-creamy frozen custard is a favorite with everyone, and I can't count how many times I've given out the recipe. I can't even put into words how amazing this frozen custard tastes; you'll just have to try it yourself, but I'll warn you, your knees make buckle with the first taste. Even my mom, who claims to hate avocados, nicknamed this recipe "Smooth Perfection." The avocados give the custard a silkiness that egg yolks alone cannot provide, and unlike other frozen desserts, this one does not get rock hard in the freezer. You can't buy ice cream or frozen custard this good! —Mary Shenk
In a heavy saucepan or double boiler, combine egg yolks, sugar, heavy cream, and salt. Cook, stirring constantly, until slightly thicken and the temperature registers 175 degrees F on an accurate thermometer.
Remove custard from heat; cover surface with plastic wrap and chill overnight in refrigerator.
Combine avocado, vanilla, almond, and lemon juice. Stir avocado mixture into chilled custard.
Freeze custard in an ice cream maker according to manufacturer's instructions.
Transfer frozen custard to an airtight container and let ripen in the freezer at least four hours before serving. Store frozen custard in the freezer.