Thick Onion Tart

The secret of this tart, with its wholewheat cheese pastry, is to cook the onions until they almost caramelise so they form a lovely thick, brown layer over the base.


Serves 4-6

This recipe is taken from Delia Smith’s Complete Cookery Course, Delia Smith’s Complete Illustrated Cookery Course and Delia's Vegetarian Collection

Thick Onion Tart
For the pastry:
 2 oz (50 g) self-raising flour
 2 oz (50 g) wholewheat flour
 pinch of salt
 ½ level teaspoon mustard powder
 2 oz (50 g) butter
 1½ oz (40 g) Cheddar cheese, grated
For the filling:
 1½ lb (700 g) onions, chopped fairly small
 2 oz (50 g) butter
 2 large eggs, beaten
 4 fl oz (110 ml) double cream, natural yoghurt or milk
 1 level tablespoon grated Cheddar cheese
 salt and freshly milled black pepper
 Pre-heat the oven, and a baking sheet, to gas mark 4, 350°F (180°C).
You will also need an 8 inch (20 cm) fluted tart tin, greased.


First make the pastry by sifting the flours, salt and mustard powder into a mixing bowl, then rubbing in the fat until the mixture becomes crumbly. Then stir in the grated cheese and add enough cold water to make a dough that leaves the bowl clean. Wrap the dough in a polythene bag and leave to rest in the fridge for half an hour.

Meanwhile, you can be preparing the filling. Melt the butter in a heavy-based saucepan, then add the chopped onions, stir to get them well coated in the butter, and cook them (uncovered) over a medium heat for about half an hour until they have reduced and turned a deep brown. Give them a stir from time to time to prevent them catching on the bottom of the pan and, if at the end of the time they haven't turned almost mahogany brown, turn the heat up and cook for a further 10 minutes.

Then roll out the pastry to line the tart tin, prick the base with a fork, place it on the pre-heated baking sheet, and bake in the centre of the oven for 15 minutes. After that remove from the oven and brush the inside of the pastry case with a little beaten egg (from the filling), and return to the oven for another 5 minutes. Then spread the onions all over the base of the tart, whisk the beaten eggs together with the cream and some seasoning, and pour as much of this mixture over the onions as possible (depending on how much the onions have reduced, there may be a tiny spot left over).

Finally sprinkle the cheese over the top, return the tart to the oven and bake for 30 minutes till the filling is puffy and golden brown.

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