I had to take a picture of this before we ate it! I did cheat a bit as I used frozen pastry - not normally something I would do but we're decorating the larder and kitchen so everything's in a bit of a mess.
4 onions (I used 2 red and 2 white)
1/4 pint milk
1/4 pint single cream
salt and pepper
Cut the onions into eighths, arrange in a baking dish and cover with a tablespoon of olive oil and salt and pepper. Roast in the oven for about 20 minutes, or until starting to turn golden. Leave to cool.
Roll out the pastry and line a greased dish. I don't blind bake because in the aga there's no need, but you might need to if you have a conventional oven.
Prick the bottom a couple of times with a fork and arrange the onion pieces in the pastry case. Cover with the mixed milk, cream and eggs and a sprinkle of cheese if you want.
Bake until golden - about 35 minutes. Sorry I can't give temperatures as the aga doesn't have them!
Serve with home-made coleslaw and lots of salad. A perfect excuse to use the new heart shaped le creuset!