Onion & Cheese Tart

I had a very large number of small onions in the pantry, due to being inspired by the price tag of $1.99 for a kilo, and last night I needed to make something for dinner. So, whenever faced with a particular ingredient that needs to be used, I turned, as many an Australian does, to Stephanie Alexander's Cooks Companion and found exactly what I needed; an onion and cheese tart.
And off I went.
The finished product is absolutely delicious - creamy and oniony and packed full of flavour. A. complained that it was "too oniony" and not the best type of thing to take to work for lunch, but I really love it!

Onion & Cheese Tart
The Cook's Companion : the complete book of ingredients and recipes for the Australian kitchen.

1 quantity shortcrust pastry (I used 2 sheets of frozen puff, as that's what I had in the freezer)
1 kilogram onions, chopped or finely sliced
80 grams butter
1 tablespoon plain flour
3 eggs
150 mls cream (I used plain yoghurt as that's what yada yada yada...)
100 grams cheese (crumbled blue or strong cheddar)
salt
black pepper
fresh thyme
1/4 teaspoon crushed caraway seeds or freshly grated nutmeg (optional)

Preheat oven to 200 C. Line a 22cm loose bottomed flan tin with pastry, then bake blind for 20 minutes. Allow to cool.
Cook onion & thyme slowly in butter in a heavy-based, non aluminium frying pan, covered, until golden and tender (about 25 minutes). Drain. Stir in flour off heat. Whisk eggs, with cream and add onion mixture and cheese. Taste for seasoning and add caraway seeds, if using.
Pour mixture into pastry case and bake at 180C for 20 minutes, or until filling is set.
Serve warm.
Serves 6.