Preheat the oven to 180C / 160C Fan / Gas Mark 4. 

Peel the pears, quarter and core them and then chop into 2cm chunks. Roughly chop the walnuts and dark chocolate - I like mine quite chunky to add texture. 

Add the pear chunks, dark brown sugar, walnuts and chocolate to a crumble dish and mix well. Set to one side.

To make the crumble, add the sugar, cubed butter and gluten free flour to a large mixing bowl. Using your fingertips, rub the flour mix into the butter, until you have a breadcrumb-like consistency.

Pour the crumble mixture on top of the pears, so the fruit is completely covered. 

Place the crumble in the oven and bake for 45-50 minutes until golden on top, and the fruit is bubbling up round the edges. Serve hot with a ball of vanilla ice-cream on top.