1. Place the cream and milk in a saucepan and heat until just below boiling point.
2. In a mixing bowl, beat together the egg yolks and sugar until thick and pale.
3. Whisk 2 tablespoons of the hot cream and milk into the egg mixture. Slowly add the rest of the cream and milk, whisking as you go.
4. Return the mixture to the saucepan and cook over a low heat, stirring continually for about 8 minutes or until the mixture coats the back of the spoon.
5. Pour into a box and refrigerate until cool.
6. Place the lemon juice in a bowl and combine with the grated apple.
7. Pour into an ice cream maker churn make according to manufacturers instructions.
8. Alternatively, pour into a metal bowl and place in the freezer for 2 hours or until set around the edges, but soft in the middle.
9. Beat with an electric beater and return to the freezer until firm.