To make your own flan case, melt the butter and allow it to cool. Grease and flour a 12in (300mm) flan tin. Separate one of the eggs, reserving the egg white, then whisk it with 3 whole eggs and the caster sugar until the mixture runs off a spoon in a thin trail. Sift the flour into the mixture and fold in carefully. Gradually fold in the melted butter.

Pour the mixture into the flan tin and bake in the centre of the oven for 25-30 minutes until well risen and the sponge shrinks slightly away from the side of the tin. Turn onto a wire rack to cool.

To make the syrup, put the sugar into a saucepan with 1/4 pint (150 ml) of cold water. Heat gently until the sugar dissolves, then boil for 1 minute and stir the optional liqueur into the syrup. Place the flan on a serving dish and carefully spoon over the syrup.

To make the filling, roughly slice 8 oz (225 g) of the strawberries, put them into a bowl with the caster sugar and mix well. Cover and leave to stand for 20 minutes, then press through a sieve to make a puree.

Put 2 tablespoons of cold water into a small saucepan and sprinkle over the gelatine. Leave to stand until the gelatine swells and becomes opaque, then heat gently until it becomes hot and dissolves completely. Whisk into the puree, then whisk in the fromage frais. Leave in a cool place until thickened.

Meanwhile, separate the egg, reserving the white, then whisk it until it forms soft peaks. Fold into the strawberry mixture and pour into the flan case. Refrigerate until set. Just before serving, use the remaining strawberries to garnish the flan and a fine sieve to sift the icing sugar over the top.