Wash the lemons and zest them until you have 1 tablespoon of lemon zest (preferably use a very fine grater for this).
Then juice the lemons and collect the juice.
Put the lemon zest and juice in a measuring jug together with the sugar and buttermilk. Stir well until the sugar has completely dissolved.
Pour the mixture into an ice cream maker and churn it into a lovely, creamy ice cream in about 20 to 30 minutes (preparation time may vary depending on the ice cream maker).
You can store the ice cream in a sealed container in the freezer for about 2 to 3 days (if you can manage to keep it that long, of course ). Enjoy!