A moreish lunch where the filling and pastry can be made in advanced.
Cook the onions and butter in a large frying pan on medium-low for about 20 minutes or until they are very soft and caramelised.
Preheat the oven to 180°C and lightly dust a work surface with flour.
Gently roll out your chilled pastry dough until you have a large, thin round.
Grab a loose-bottomed 20cm springform cake tin, and gently drape the pastry over your rolling pin and then unroll into the tin.
Press into the tin’s base and up the sides and trim the edges with a sharp knife. Return to the fridge for half an hour.
Whisk together the cream, eggs, Parmesan and thyme and season to taste.
Scatter the base of the pastry shell with the caramelised onions, pour over the cream mixture and then dot the top with the tomatoes.
Cook for about 30 minutes or until the quiche is golden brown and feels just firm on top. Let cool for at least 20 minutes then serve.
Serve with a green salad.