1. Halve the pomegranates and knock out the seeds of one by hitting the back with a wooden spoon. Let the seeds fall into a bowl and set aside for garnish.
2. Take the other 3 and squeeze the juice, preferably in an electric juicer. Place the juice in a small saucepan and boil to reduce to approximately 100ml or until it thickens slightly and becomes syrupy. Allow to cool.
3. Combine the mascarpone and cream and whisk until just blended. Whisk in the pomegranate syrup and sugar and freeze in a plastic container. Allow to soften before serving.
4. Scoop the ice-cream on to a plate ? or shape into quenelles with two tablespoons ? and sprinkle over the reserved seeds.