1. COMBINE the chocolate and condensed milk in a small saucepan and gently heat until the chocolate has melted and the mixture is smooth. Transfer mixture to a freezer proof bowl and chill in the freezer for 15 minutes.
2. BEAT the chocolate mixture using an electric mixer until smooth. Beat in the cream until thick and soft peaks form. Spoon ½ of the mixture into a lined 22cm square cake pan. Colour the remaining mixture with food colouring, then spoon over white mixture. Drag a knife through the mixture lightly to give a marbled effect. Cover and freeze until firm.
3. REMOVE the ice cream from the tin and cut in to five thick slices. Cut each in half again and assemble in serving dishes with the banana a drizzle of topping and decorations. Serve immediately.