Onion, Cheese and Chard Tart

I'm sure that I'm not the first person to point this out, but the onion really is underrated.  Nearly every dish we cook, curries, pasta sauces, stews, you name it, the onion has a starring role but it never gets any of the credit.  Tonight Z has settled the score with an onion, cheese and chard tart.  The reason Z is cooking an onion tart is a surfeit of onions. 

At fifty pence for a couple of pounds of them I was hardly going to say no.  The chard was the last of our crop from the front garden.  We have grown nowhere near enough chard this year but as the old saying goes, your garden is never as good as it will be next year.

To make the filling for the tart, Z slowly sweated three onions in olive oil and butter until they were soft before adding the chopped chard stems.  These take a little longer to cook than the leaves which cook in next to no time so they were just stirred through the onion and stalk mixture as it cooled.  Other than salt and pepper the only addition to the naturally sweet mixture was lemon thyme.

Once cool, the onions and chard were spread over a sheet of rolled out puff pastry* and then covered with cheese.  We happened to have in a few ends of cheeses so four different types were used on our tart, but as long as you have a decent melting cheese any will do.  By the time the tart had baked and the sides had risen, a miracle had occurred, the sky had cleared and the sun was out. A perfect summer's evening for a perfect summer meal.

*shop bought. I know that this will outrage some people but there are some things that are worthy of shortcuts and puff pastry is one of them