400ml apple juice
150g caster sugar
1 lemon, juiced
Give the beetroot a wash, then put them, whole and unpeeled, in a pan of water. Bring to a boil and simmer until tender - 30 minutes to an hour-plus, depending on the size of the beetroot. When they are cooked, drain off the water and leave them to cool. Once cool, peel and cut into rough chunks.
Put the apple juice, sugar and lemon juice into a small pan, heat gently until the sugar dissolves, then set aside to cool.
When the beetroot and syrup are cold, tip both into a blender along with the vodka. Whizz to a puree.
Chill the mixture for an hour.
Freeze the beet puree in an ice-cream maker