In a pan add the rhubarb, apples dates, apple concentrate, lemon juice, water, cinnamon, and cloves. Slowly bring to the boil then reduce to simmer. Cook for 5 minutes until the rhubarb is tender but still retains its shape. Strain the rhubarb, reserving the liquid and returning it to the pan. Mix the cornflour in 1 tbs water and add it to the reserved rhubarb juice. Heat the liquid gently stirring it until it thickens. Pour the sauce over the rhubarb and apple. Set aside to cool.
In a food processor combine the flours with the salt and cinnamon. Mix the table spread with the apple concentrate and add to the food processor (with the dough blade) Process until combine and resembling breadcrumbs. Add enough ice cold water to the dough slowly until it forms a ball that is smooth and pliable. Cover with plastic and chill for 30 minutes.
Preheat oven to 180 degrees Celsius.
Roll out on a floured board making a rough circular sheet of pastry approx 40 - 50 cm in diameter. Lay the pastry onto a flat baking tray lined with baking paper. Pile the fruit mixture into the centre of the pastry and fold the ends up and around the fruit and back towards the centre.
Bake in the oven for approx 30 minutes.
Serve with yogurt or a non dairy alternative.
Note : Spelt flour and oatmeal both contain some gluten and are not suitable for people suffering from coeliac disease.