Start by placing a sheet of gelatine leaf into a bowl of cold water and leave to soak.
Next, chop the rhubarb into 5cm lengths. Then add them to a saucepan with the caster sugar and water. Bring to a slow boil and then simmer until the rhubarb has softened, approximately 10 minutes. Once soft, remove from the heat. Squeeze the excess water out of the gelatine leaf and mix through the rhubarb.
Scoop a tablespoon of the rhubarb into a clean glass of your choice. Place in the fridge for an hour and a half to set.
Now, onto the jelly. Place the remaining six leaf gelatine in a bowl of cold water. Leave these to soak until soft.
Next, over a medium heat add 150ml of the sparkling wine with the caster sugar. Once the sugar has dissolved, squeeze and add the gelatine and remove from the heat. Whisking continuously.
Now gently stir in the remaining sparkling wine trying to keep as many bubbles as you can.
Allow the jelly to cool and pour carefully over the rhubarb base and place in the fridge to set again. Ideally overnight.
Whilst setting, whisk the cream to soft peaks and grate and fold the lemon zest through.
Serve the jelly and top with a lovely dollop of fresh zesty cream.