caramelised onion & tomato tart

It's still winter - still very definitely winter, in the frigid part of the world I live in - but I'm ready to stop eating as if it's winter. We had fresh snow last night, but earlier in the week I walked outside without a coat and was so startled to hear birds that I thought, for a moment, a poltergeist had hit play on my stereo. So in that brief respite I made myself a spring-like lunch: this caramelised onion and tomato tart.

The inspiration for this tart is Claudia Roden's Alsatian onion tart in The Book of Jewish Food (US, UK). That tart, tomato-less and heavier with onions, is one of my favourite things to eat. Onions are robust once caramelised, I know, but the perfect poise of this creamy filling is light and delicate. It also suggests alternatives to its purity: some leeks, some truffle salt, perhaps (every now and then) some bacon. Or, in optimistic honour of the coming warmth, vine-ripened tomatoes and flecks of freshly ground pepper. Perfect for lunch with a fresh green salad.



Caramelised Onion & Tomato Tart
adapted from Claudia Roden's Tarte aux Oignons d'Alsace

For the pastry:
125g unsalted butter
250g plain flour
1/4 tsp salt
1 egg, lightly beaten
1-2 tbsp milk (if required)

For the filling:
1 large onion
25g butter
2 tbsp sunflower or light vegetable oil
salt
2 tbsp plain flour
250 ml light double cream
2 eggs, lightly beaten
white pepper
2 ripe tomatoes
salt & freshly ground black pepper

To make the pastry: cut the butter into small pieces and rub it into the flour and salt with your hands. Add the egg, mix well, and work very briefly with your hand until bound into a soft sough, adding a little milk if necessary. Cover in plastic wrap and refrigerate for 1 hour.

To make the filling: cut the onion in half, then into thick slices. Heat the butter with the oil in a large pan and cook the onion over very low heat and with the lid on for about 1 hour, or until very soft and lightly coloured, stirring occasionally and adding a little salt. Now add the flour and stir well. Beat the cream into the eggs. Let the onions cool a little before sirring into the cream mixture. Taste before adding a tiny bit of salt if necessary and pepper. The tart should not be too salty.

Preheat the oven to 300 Fahrenheit / 150 Celsius / gas oven 2.

Slice the tomatoes 1/2 a centimetre thick, place the slices to drain on a paper towel, and sprinkle with a little salt.

Line a greased 25cm tart pan or rectangular tart mould with the dough by pressing it in with the palms of your hands (easier to do with this soft dough than to roll it out) and pressing it up the sides. Pour in the creamy filling, then top with tomato slices. Bake for 1 hour, or until set and golden. Serve hot or cold, with freshly ground black pepper.