Line the flan dish with the pastry, trim and chill for 20 minutes.
Put the flan dish on a baking sheet, line the pastry-case with greaseproof paper or tin foil and fill with uncooked pasta to weigh down. Bake in the oven for 10 minutes, then remove the paper and pasta.
Cook for 5 more minutes after pressing down with a fork.
Reduce the oven temperature to 190ºC.
Melt the butter in a pan. Gently soften the leeks for 5 minutes. Remove from heat and leave to cool.
Cut the goat’s cheese into small pieces. Halve the tomatoes.
Beat the eggs lightly, stirring in the crème friache, chives and salt and pepper to make a creamy mixture.
Spread the leeks over the pastry, dot with the goat’s cheese and cherry tomatoes (round side up). Pour the egg mixture over the filling. Sprinkle with the parmesan.
Bake in the oven for 25-30 minutes until filling is golden on the top and firm to the touch.