A tart for lunch, supper or a party

2. Set the oven at 220C/425F/gas mark 7. If you're using a sheet of ready-rolled pastry, simply roll it on to a lightly floured baking sheet. If you're using a block of pastry, roll it out into a rectangle (or square or round) no thicker than a 10p piece. Score a border 2cm from each edge and prick all over with a fork.

3. Tip the onions on to the pastry, pushing them almost, but not quite, to the border. Brush the rim with some of the onion butter. Slice the cheese quite thinly, then break it up into small pieces, tucking it in among the onions. Scatter over the thyme.

4. Bake until the pastry is golden and puffed and the onions browning – 15 to 20 minutes.

And more

• A leek and Taleggio tart. As above, but with leeks. The essential point is not to let the leeks colour too much – they turn bitter when even slightly charred, so you may find you need a little more butter. I find it helps to put a piece of greaseproof paper and a lid over the leeks while they're cooking, to stop them browning.

• An onion and camembert tart. I have used Brie, too. Both work and give a deeply savoury, melting result.

• A tomato and basil tart. Something for summer and autumn. Spread a thick layer of pesto on the puff pastry, then cover it with thin, though not too thin, slices of tomato. Crack over lots of black pepper and sea salt, then bake till crisp and golden.

• A pancetta and onion tart. I think there are two ways you could go about this. I've added chopped pancetta – about the size of Dolly Mixtures – to the cooked onions as the tart goes in the oven but I've also had success (if that's what you call it when every last crumb gets eaten) with scattering thin slices of pancetta, cut into pieces the size of a postage stamp, over the onions before I tuck in some Camembert or Brie.

• A red onion and Parmesan tart. You get that wonderful sweetness with red onions so redolent of contemporary Italian cooking, and they work well, as you might imagine, with the depth of savour you get from Parmesan cheese. Cook the onions as above, spread them over the pastry, cover them with a thick layer of grated Parmesan (some thyme would be good here too) and bake as above. Be generous with the cheese.