Onion and Blue Cheese Tart

I'd like to have put the word 'winning' in the title of this recipe, but I was just pipped to the post by my friend Matt Allison, whose Onion and Biltong Tart walked off with top honours at the recent Ommiberg Onion Tart Cook Off. I couldn't begrudge Matt his win: his choice of biltong was inspired, and he magicked up a very fine tart indeed, as did the other competitors, my pals and fellow food bloggers Jessica Ulyate and Linda Harding.

Clockwise, from top left: Matt's Onion and Biltong Tart, Jessica's Onion and Pear Tart, Linda's Onion and Confit Pork Tart, my Onion and Blue Cheese Tart

Cooking under pressure, and in public, was something I'd never tried before, and I enjoyed every minute of it, except when a TV cameraman poked his lens into my face (a stomach-churning moment for a camera-phobe like me). Quite by chance, the cameraman in question turned out to be an old and dear friend, musician Carl Raubenheimer, so as you can imagine I did not hold back on threats and insults.

This is how the cook-off worked: we were given a pre-cooked pastry shell,  and some basic ingredients - eggs, milk, onion and Cheddar - and asked to choose (in advance) our own secret ingredients.

Food bloggers: (left to right:) Jessica Ulyate, Linda Harding and Matt Allison, with one of the judges, chef Neill Anthony, at the back.

Before I settled on blue cheese, I tried out various secret ingredients (by making a big batch of filling, dividing it between six ramekins and adding a different ingredient to each). The six 'candidates' were smoked Franschhoek trout, Boursin garlic and herb cheese, blue cheese, roast chicken and marinated artichoke hearts. After a taste test, and input from my husband and son, blue cheese came out tops (with Boursin a close second).

Then I tried three blue cheeses: first a pungent Roquefort, then a squashy Italian gorgonzola, and finally Fairview's Blue Tower, which had the right balance of pungency and creaminess. As I tested the recipe,  I also juggled the proportion of milk to egg to get just the right creamy 'set'. (In an nutshell: four eggs to 125 ml milk.)

I also wanted my tart to deliver a Full-Monty onion experience, so I used the onions in different ways:  finely chopped and slowly seethed in olive oil (for the filling); thinly sliced and caramelised in butter (for the topping). For punch, I added a tablespoon or so of  raw onion juice.

Chef Neill Anthony, one of the judges, paying serious attention to a slice of tart

We were restricted to just one secret ingredient, but if we had not been, I would have added fresh thyme to the mixture, and topped the tart with a sprinkling of poppy seeds. I would also have added a little fresh cream to the egg mixture. (If you'd like to do the same, use a tablespoon - 15 ml - chopped fresh thyme leaves, and substitute half the milk for single cream).

Make sure the blue cheese is very cold, or it will not grate well.

My thanks to Rhebokskloof wine estate, Ommiberg Wine Festival, Neill Anthony, and Illanda Smit of Erica Meles PR, and also to Fairview and Yuppiechef for some lovely prizes.

Note: I'm not sponsored by Fairview; I just like their cheese!

Onion and Blue Cheese Tart

For the pastry shell:
250 g white flour
a pinch of salt
150 g cold butter, cubed
2 egg yolks

For the filling:
4 medium onions, peeled
2 T (30 ml) olive oil
4 T (60 ml) butter
4 large free-range eggs
1/2 cup (125 ml) milk
1 cup (250 ml) grated Cheddar (loosely packed into the cup measure)
1 cup (250 ml) grated mild blue cheese (loosely packed)
salt and milled black pepper

Preheat the oven to 180° C. To make the pastry shell, sift the flour into a bowl and add the butter. Using your fingertips, rub the butter into the flour until the mixture resembles fine breadcrumbs. (Or blitz in a food processor fitted with a metal blade). Now stir in the egg yolks, and combine to form a stiffish dough. (Add a few drops of iced water if the mixture seems too stiff). Put the dough in the fridge for 10 minutes, then roll out and use it to line a greased 23-cm quiche or flan dish. (Click here for my top tips for making pastry.)

Prick the bottom of the pastry shell all over and bake blind. Set aside to cool.

(Alternatively, if you're feeling lazy and don't mind a slightly soggy crust, simply press the pastry across the bottom and up the sides of the dish, using your fingertips, and then add the filling).

Now make the filling. Finely chop two of the onions. Heat one tablespoon (15 ml) of the olive oil and 2 T (30 ml) of the butter in a frying pan. Add the finely chopped onions to the pan, toss to coat, cover with a circle of baking paper (or the paper wrapping from a butter block) and gently sweat the onions for 10-12 minutes, or until tender. Tip onto a plate and allow to cool.

While the onions are sweating, put the eggs and the milk into a mixing bowl and, using a wire whisk, beat well for one minute. Add the grated Cheddar and blue cheese.

Grate a third of one of the remaining onions. Place the pulp in a sieve over the mixing bowl and press down hard to extract a teaspoon or two of raw onion juice. Discard the grated pulp.

Very finely slice the remaining onions into paper-thin rings (use a mandolin, if you have one). Heat the remaining oil and butter in the frying pan, add the onion rings and cook, stirring often, over a brisk heat for 4-5 minutes, or until the rings are golden brown and caramelised. Watch them like a hawk, as they burn quickly.

Tip the cooled, sweated onions into the egg mixture. Give the egg mixture another quick whisk, season with salt and pepper to taste, and pour into the prepared pastry case. Arrange the fried onion rings on top. Bake at 180° C for 30-40 minutes, or until puffed and golden. The centre of the tart should have a very slight wobble.

Serve hot or warm, with a green salad.

Makes one 23-cm tart; serves 6-8

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