Method

1. Line base and sides of a 20cm round springform tin with baking paper. Put in freezer for 30 minutes.

2. Set ice-cream aside for about 5 minutes to soften slightly. Put 2½ cups of the ice-cream in a bowl. Tint with green food colouring until you reach the desired colour and stir until ice-cream is fully coloured. Return remaining ice-cream to freezer. Evenly spread green ice-cream around inside edge of prepared tin to form watermelon rind. Freeze for 30 minutes.

3. Set plain ice-cream aside for 5 minutes to soften slightly. Evenly spread 1 cup of the plain ice-cream over inside edge of green layer. Return tin and remaining ice-cream to freezer and freeze for 30 minutes.

4. Set remaining plain ice-cream aside for about 5 minutes to soften slightly. Tint with red colouring until you reach the desired colour and stir until ice-cream is fully coloured. Stir in chocolate chips. Spoon into centre of tin and smooth surface, taking care not to mix colours. Freeze for 8 hours or preferably overnight.

5. Remove cake from tin, and put on a serving plate. Cut into wedges to serve.