Don’t worry that this has Stilton in it, even people who blanch at the merest whiff of blue cheese (namely my mum) love it. It has a base of sweet caramelised balsamic onions, the cheese mellows in the oven and the walnuts (which are suspiciously absent in the picture above) add a good bitter crunch. No Christmas is without it in my household.
It comes from such an old Good Food that the recipe’s not even on the internet and only needs five ingredients. Firstly onions. Slice 6 medium ones. If you have food processor clomp them through the slicer attachment to reduce the amount of tears shed. Now there are two options. The conscientious way is to slowly caramelise the onions, which will take about an hour. Cook over a low heat with the lid on for ten minutes, then take the lid off and continue for another 50 minutes until the onions have softened right down. Stir every few minutes, scraping all the sticky bits from the bottom of the pan as you go. If you don’t have the time for this, once the lid is off, turn up the heat to medium and stir in a dessertspoon of sugar. Then cook, stirring often, for another ten minutes. The sugar’s a shortcut to the sweetness you would get from the long, slow cooking of the onions. Either way, once they’re done, add a good tablespoon of balsamic vinegar and let it bubble away, then leave to cool. The onions can be cooked the day before you make the tart if you want to get ahead.
Next, puff pastry. Dust a baking tray with flour and roll out half a 500g block of pastry to fit the tray. Spread your onion mixture to within an inch of the edges, then crumble over 150-200g of stilton and a handful of chopped walnuts. If you forget the walnuts, ahem, just sprinkle them over when the tart is out of the oven. Now cook at 180C for about half an hour, or until the pastry is crisp and puffed up around the edges.
This makes a nice tea with a green salad but is perfect chopped up into squares for feeding a crowd.