Ingredients

Serves 8-10Prep time: 10 minutesCooking time: 1hr-1hr 20 mins100g butter, softened225g Sainsbury's Fairtrade caster sugar2 medium eggs, lightly beaten4 Sainsbury's Fairtrade bananas, peeled and thoroughly mashed225g plain flour, sifted2tsp baking powderPinch salt50g shelled walnuts, choppedMethodPreheat the oven to 180C/fan 160C/gas 4. Grease and line a 20 x 12cm loaf tin.

Beat together the butter and sugar until creamy, then gradually stir in the eggs, little by little until fully incorporated. Stir the mashed bananas with the flour, baking powder and salt into the mixture until well blended, then fold in the nuts.

Spoon into the prepared tin and bake in the oven for one hour to one hour 20 minutes until well-risen and golden brown. Transfer to a cooling rack and serve in slices.

Grigson says: "An increasing range of Fairtrade food is now available at a variety of shops and supermarkets.

Sainsbury's range includes bananas which are 100 per cent Fairtrade and a large percentage come from the Windward Isles, including St Lucia."