Sorbetto di arancia

1.Using a food processor, process orange and icing sugar until finely chopped. Transfer to a jug and add 450ml orange juice. Combine remaining orange juice with glucose in a small saucepan and cook over low heat until glucose dissolves (1-2 minutes). Cool, add to jug and stir to combine. Refrigerate until completely cold (20-30 minutes). Freeze using an ice-cream machine according to manufacturer’s instructions. Makes about 1 litre. Serve sorbetto with amaro poured over to taste.