This pie would make a wonderful centrepiece for a family meal. My granddaughters Abby and Grace helped me to make it for the TV programme. For this recipe you will need a 1.75 litre/3 pint shallow, wide-based ovenproof dish, about 25cm/10in in diameter.
The rhubarb tart on its own is quite sharp, so the sweetened mascarpone cream helps to balance the dessert. This cream works wonders with any soft fruit.