Trim the rhubarb into short lengths and place into a saucepan with 1 tbsp water, brown sugar and ginger. Bring to simmering point and cook gently for 10 – 15 minutes until soft. Allow it to cool and when almost cold, liquidise with the custard. Chill and divide into six glasses decorated with grated curls of chocolate or lightly poached pieces of rhubarb or both !