I don't know why I've had quiche and savoury tarts on my mind recently, but the idea has been niggling at me for about a month. So, when we got onions in the veg box for the 3rd week running, and somehow I hadn't used any of them, I decided that it was time to give in and make an onion tart. I prepared the onions the day before, which is the really time consuming bit, so then it was a pretty speedy Monday night dinner.
1 sheet ready-rolled shortcrust pastry
1 metric fuck-tonne of onions (I think it was 9 medium onions and 3 red shallots - basically keep peeling and slicing until your patience runs out)
1tbs olive oil
1 sprig of thyme
150g mild cheese (I used a firm goats cheese, but the goat naysayers could use a mild cheddar, or gruyere)
150ml sour cream
Heat a heavy-based saucepan with a lid over a low heat, add the olive oil and butter and when the butter melts add the thinly sliced onions and the thyme. Turn the onions over in the melted butter and oil until well coated, then cover tightly and cook in a slow oven until, as the Hairy Bikers say, "wilted to the point of apathy". These had an hour at 120C. If you haven't got anything better to do, you can do the onions on the stove top, stirring frequently. Basically you want them completely collapsed, translucent and beginning to take colour. If you try and hurry this stage, the onions will burn or, even worse, stay raw. And raw onions in this quantity lead to soggy pastry and unsettled tummies.
Let the onions cool.
Grate the cheese into a mixing bowl and add the sour cream and eggs, beating well. Add the cooled onions and season well with grated nutmeg and black pepper.
Line a pie dish with the pastry, prick all over with a fork and blind bake for 10 minutes at 180C, just to begin to set the pastry.
Pour the onion mixture into the pastry case and return to the oven, baking for about 35 minutes, or until golden and puffy. Allow to sit for 15 minutes to firm a little before cutting, and serve with a sharply-dressed green vegetable or salad. We had steamed purple sprouting broccoli dressed with lemon juice and garnished with some panko breadcrumbs, tossed with olive oil, garlic and lemon zest until golden and crisp.