Rhubarb and walnut crisp

Method

1. Heat the oven to 190°C/fan170°C/gas 5. Spread the walnuts over a baking tray and roast for 4 minutes until they have darkened slightly and smell nutty. Leave to cool, then coarsely chop by hand.
2. For the topping, sift 100g of the flour and the cinnamon into a bowl, then rub in the butter until the mixture looks like coarse breadcrumbs. Stir in the demerara sugar and chopped walnuts.
3. Cut the rhubarb into 2.5cm pieces and put into a mixing bowl. Cut the pared orange zest across into small, thin pieces that resemble pine needles, then add them to the rhubarb with the grated ginger, caster sugar and the remaining flour. Mix together well and set aside for 15-20 minutes, stirring now and then, until the fruit is covered in a moist, sugary-floury mixture.
4. Spread the fruit in a shallow 2 litre ovenproof dish and sprinkle over the topping. Bake in the oven for 45 minutes until the rhubarb is tender and the top is golden brown. Serve with clotted cream.