Tapioca didn't dissolve. I took all the hard bits of tapioca out and broke up the filling and biscuit crust. Used it to make a layered yoghurt dessert for guests, with a touch of icecream..Sadly for me, this recipe needs more work.
I made this for a family Sunday lunch, everyone enjoyed it, even those who hate rhubarb! I followed the recipe exactly but I made a biscuit pastry (will add the recipe) with a thick egg white and sugar wash. Served it warm with thick cream. I will definately add this to the family favourites.