Mix together thei milk, sugar, orange zest and orange juice. Chill, stirring occasionally, until the sugar has dissolved. Transfer to an ice cream maker and process, or pour into a freezer container and use the hand-mixing method. When almost firm, leave in the freezer for at least 15 minutes or until required.

To make the topping, heat the marmalade with the orange juice and zest, cool a little, then pour over sherbet.

This sherbet can be stored in the freezer for up to 3 months. Take out 5-10 minutes before serving to soften.