Not to be confused with Quiche Lorraine, French Onion tart really is what it says. Onions. With a bit of cream, cheese and eggs. But don't let the apparent simplicity fool you - it is a real treat, especially if enjoyed al fresco. In fact, it really comes into its own served at picnic hamper temperature. There's a bit of room to get creative with the pastry too. A few fresh thyme leaves, a little Dijon mustard and even a splash of wine all add a little je ne sais quoi.
To make the pastry, pulse the flour, butter, thyme, mustard and half a teaspoon of salt in a food processor until the mixture looks like breadcrumbs.
Tip into a bowl then gradually add iced water (or wine) , stirring with a knife, until it comes together. Wrap in clingfilm and chill for 30 minutes.
For the filling; melt the butter in a large pan, add the onions and cook over a low heat, stirring occasionally, until they're golden and meltingly soft.(approx 30 minutes)
Heat the oven to 180°C
Roll out the pasty to the thickness of a 20p piece on a lightly floured surface.
Carefully line a shallow - approximately 22cm - tart tin.
Leave the excess pastry overhanging. Sit the tart on a baking sheet. Line the pastry with baking paper and fill with baking beans.
Bake for 15 minutes, then remove the beans and paper and cook for another 5 -10 minutes until there are no raw patches.
Leave to cool for five minutes. Trim off the excess pastry while it is still warm with a small serrated knife.
Whisk the cream, eggs and cheese together and season well.
Arrange the onions in the pastry case then pour over the egg mix.
Slide the case back in the oven for 15 - 20 minutes or until the filling is just set. Serve warm.