For the custard
Put the milk (or milk and cream) in a pan and let it come to the boil.
Set aside and allow to cool slightly then pour it onto the sugar and yolks in a basin and mix well.
Return it to the pan and keep stirring until it thickens and clings well to the spoon, but do not let it boil.
Pass it through a tammy, hair sieve or strainer. Let it cool in fridge overnight.
For the ice-cream
Stone the cherries, break the stones and take out the kernels.
Cook the cherries and kernels for about 10 minutes in the water and sugar.
Pound them (Agnes really didn't like bits in her ice-cream!) and add the lemon juice and a little red food colouring.
Pass through a tammy cloth or hair sieve and add to the custard and kirsch and freeze.
If using a modern-day ice-cream maker churn time is about 25 minutes.