Onion Tart

Pre-heat oven to 180oC, 350oF, Gas 4.

To make the pastry

1. Sift the flour and salt into a large bowl.
2. Cut 70g of the butter into small dice ( it should be soft at room temperature)
3. Rub the butter into flour, using your fingertips.
4. When the mixture looks like breadcrumbs, make a well in the middle and add the water.
5. Using your fingers, lightly mix until the dough forms a ball. If it seems too dry add a little more water, but try to handle lightly – do not knead!
6. If there is time, wrap the dough in cling film or place in a polythene bag and leave it to rest in the fridge for half and hour.

To make the filling

1. Peel the onions and slice thinly.
2. Melt the remaining butter in a heavy based saucepan over low heat and add the sliced onions.
3. Stir well to coat the onions, and cover the pan. They should stew gently over the next half-hour and get really soft.
4. Give them a stir with a wooden spoon from time to time to check that they are not sticking or turning brown.

Assemble

1. Turn dough out onto a floured surface and form into an even round shape.
2. Flour your rolling pin and roll the pastry out until it is 3-4 mm thickness. Remember to keep flouring the surface and rotating the pastry to prevent the dough from sticking.
3. Lift it carefully onto your flan tin or dish, easing it down into the corners.
4. Trim off any surplus pastry, neaten the edges and put it in the fridge to rest whilst you prepare the filling.
5. Put the cooked onions into a bowl and let them cool slightly. Add most of the cheese and eggs, and season to taste.
6. Pour the mixture into your prepared pastry case, and sprinkle on the remaining cheese.
7. Arrange tomato slices around the edge if you like.
8. Bake for about 30 minutes, or until the filling is set and turning golden brown on top.