1.
Grease a 25cm round springform tin.
2.
Work sifted flour, margarine, 1 egg and 1 pinch salt into a smooth dough. Cover and chill for at least 30 minutes.
3.
Meanwhile, fry bacon in butter. Add onions and fry over very low heat for 30 minutes. Set aside and cool slightly.
4.
Preheat oven to 220 C / Gas 7.
5.
Line base and sides of prepared tin with dough. Fill with onion mixture.
6.
Beat together remaining eggs with cream, salt and pepper. Pour over the onion mixture. Sprinkle with caraway seeds and bake for about 40 minutes or until the top is lightly browned.