For the Syllabub, zest the lemon and lime into a bowl with the cream, sugar and sherry and whisk until nice stiff peaks.
Melt the butter and leave to cool a bit. Whisk the egg whites, butter and flour until smooth and then pour in the melted butter. Spread the mix on a silpat or baking paper as thinly as possible and bake at 180* for 8 to 10 min until golden brown. Leave to cool.
Cut the Rhubarb into 5cm long batons and place in a bowl. Zest the orange over the rhubarb and mix well with the sugar. Place it all into a shallow roasting tray tightly packed together and cover with foil. Put in oven at 180 for 12 to 15min or until rhubarb is soft. remove the tray from the oven, remove the foil and leave to cool in its juice.
Place a few pieces of Rhubarb in the bottom of a glass with a little bit of the syrup and top with the syllabub. Break a few pieces of the tuille and stick out the top.
«You could strain the liquid from the rhubarb and add gelatine to it at 3 leaves to 500 ml and spoon this into the glass and leave in the fridge for 2 hours before plating the rest of the dessert for another texture.»