Set the oven to 180 C / 350 F to bake the pastry first. Then the temperature will have to be turned down to cook the filling

Place the flour and butter into the food processor and process together. Beat the 1 egg for the pastry with the cold water then add most of the egg mixture to the food processor when it is stopped (reserve about a teaspoon), keeping aside a small amount, process until a ball forms. The extra water is just in case the pastry is a bit crumbly and doesn't form into a ball. You will most likely not need it. A crisper pastry is formed with less water.

Turn onto a bench flatten and wrap in plastic, rest in the refrigerator 30 min.

Roll out the pastry on a floured surface and line the tin with the pastry pushing it into the corners and trimming if you like. I like to leave the trimming till it is baked so there is no shrinking.

REST again, 20 minutes. Bake the case filled with baking beans or rice for 15 minutes then remove the paper and beans and bake till golden. Cool slightly and trim the sides if doing this now.

Turn the oven down to 160 C or 320 F

Spread the quince onto the bottom of the tart case very carefully. Cracks will cause leaks and leaks will cause heartache. Sprinkle over the walnuts.

Discarding the rind of the cheese, place blobs of it all over the base of the tart case ( as shown).

Mix the eggs and thickened cream combining very well, and add a sprinkling of salt.

Pour this carefully between the blobs of blue cheese

Return to the oven and bake for approximately an hour. The tart will turn a lovely golden yellow colour but will probably be quite soft and wobbly. It will firm up as it cools. Don't be tempted to cook it until it is set. This will mean that you will have to cut it with a band saw

Eat straight away or refrigerate in a covered container in the fridge.