Take the panna cotta ring out of the blister. Put on a plate and cover with plastic. Defrost in the fridge.
Mix the water with the gelatine powder and leave to rest. Bring the cream with the sugar to a boil. Melt in the gelatine mass and remove from the heat. Add the yoghurt and the rosewater. Transfer to a 1 l siphon bottle and add 2 gas cartridges. Place in the fridge. Shake well before use.
Cut the rhubalkb in balks and slice thinly with a mandolin. Place on a baking tray with silicone mat. Drizzle with the Roast & Fry and sprinkle the icing
sugar. Roast at 200 °C for 5 minutes.
Bring the beer with the sugar to a boil. Reduce on a low heat until it reaches a caramel thickness.