Onion, Walnut and Mushroom Tarte Tartin

This makes a substantial main course that's full of flavour and it can be prepared up to the baking stage a day in advance

1. 1

   Heat oven to 200c/180c fan/gas 6. Peel the onions and cut each into six wedges through the root. Heat the oil in a large pan, add the onions, then gently fry for 20 minutes until softened and lightly coloured.
   
   Add the mushrooms, sugar, salt and pepper give it a good stir. Gently cook, stirring now and then for a further five minutes. Stir in the walnuts.
   
   Line the base of a 20-23cm sandwich cake tin (not loose-based) with baking parchment. Spoon over the onion mixture and press it down lightly. Crumble the cheese over.
   
   Roll out the pastry and trim to a round, about 5cm larger than the tin. Put the pastry over the filling and tuck in the ends.
   
   Bake for 35-40 minutes until the pastry is crisp and golden. Cool for five minutes in the tin, then turn out onto a flat plate and cut into wedges. Serve with a green salad.