Cheese and Onion Flan

Ingredients:
15 gr (½ oz) (1 tbsp) butter
1 onion, halved and sliced
2 eggs
250 ml (1 cup) single (light) cream
225 gr (8 oz) strong semi-soft cheese, rind removed (about 175 gr / 6 oz without rind), sliced
salt and ground black pepper
salad leaves, to serve
For the yeast dough:
10 ml (2 tsp) dried yeast
120 ml (½ cup) milk
5 ml (1 tsp) sugar
1 egg yolk
225 gr (8 oz) (2 cups) plain (all-purpose) flour
2.5 ml (½ tsp) salt
50 gr (2 oz) (4 tbsp) butter, softened

Directions:
To make the dough, place the yeast in a bowl. Warm the milk in small pan until it is at body temperature and stir into the yeast with the sugar. Continue stirring until the yeast has dissolved completely. Leave the yeast mixture to stand for about 3 minutes, then beat in the egg yolk.
Put the flour and salt in a food processor fitted with a metal blade, and pulse to combine. With the machine running, slowly pour in the yeast mixture. Scrape down the sides and continue processing for 2-3 minutes. Add the softened butter and process for another 30 seconds.
Transfer the dough to a lightly greased bowl. Cower the bowl with a dishtowel and allow to rise in a warm place for about 1 hour until the dough has doubled in bulk.
Remove the dough from the bowl and place on lightly floured surface. Knock back (punch down) the dough. Sprinkle a little more flour on the work surface and roll out the dough to a 30 cm (12 in) round.
Line a 23 cm (9 in) flan tin (quiche pan) or dish with the dough. Gently press it into the tin or dish and trim off any overhanging pieces, leaving a 3 mm (⅛ in) rim around the flan case. Cover with a dishtowel, set aside in a warm place and leave the dough to rise again for about 30 minutes, or until puffy.
Meanwhile, melt the butter in a heavy pan and add the onion. Cover the pan and cook over a medium-low heat for about 15 minutes, until softened, stirring occasionally. Remove the lid and continue cooking, stirring frequently, until the onion is very soft and caramelized.
Preheat the oven to 180̊C (350̊F) (gas: 4). Beat together the eggs and cream. Season and stir in the cooked onion.
Arrange the cheese on the base of the flan case. Pour over the egg mixture and bake for 30-35 minutes until the base is golden and the center is just set. Cool slightly on a wire rack and serve warm with salad leaves.