75 grams butter
175 grams plain flour (Spelt is nice, low in gluten)
250 grams tasty cheese, grated
½ level teaspoon mustard powder
pinch cayenne
2 tablespoons water
1 egg, beaten

Pre-heat the oven to 180°C. Grease a 30 cm flan tin that has a removable base.

Place all ingredients for the cheese pastry, except the water and egg, in a food processor and blend till well combined. Add the water and process until the mixture forms a ball. If you don’t have a food processor, rub the butter into the flour, add the cheese, mustard and cayenne, then with your hands, mix together with the water until the dough forms a ball.

Place the dough in plastic wrap to rest in the fridge for 20 minutes.

While the pastry is resting, make the filling. Melt the butter in a heavy-based, medium-sized saucepan. Stir in the onions, balsamic vinegar and chopped sage. Season and let everything cook very gently without a lid, stirring often, for about 30 minutes until the onions have reduced and all the excess liquid has evaporated away. Let the filling cool.

Then roll the pastry out thinly and line the greased tin. Place in the fridge again for another 20 minutes. It’s important that the pastry has time to stretch before baking. If you don’t do this, the sides of the pastry will slide down to the base during baking.

Bake in the oven for 15-20 minutes or until the pastry is cooked through but not coloured. Cool the pastry slightly.

Brush a little beaten egg on to the pastry case and pop it back into the oven for another 5 minutes – this helps to provide a seal for the pastry and from becoming soggy. Spoon the onion mixture into the case. Top onions with slices of goats’ cheese and sage leaves that have first been dipped in olive oil.

Finally, sprinkle with a little cayenne and bake for 20 minutes.