Start this recipe the day before serving. Preheat the oven to 150°C (300°F/Gas 2). Line two baking trays with baking paper which have been marked with three 20 cm (8 inch) diameter circles or 28 x 12 cm (11 x 4 3/4 inch) rectangles.

To make the meringue discs, sprinkle the egg whites with the cream of tartar and whisk until stiff. Mix the cornflour with the sugar, then add to the egg whites, 1 tablespoon at a time, whisking well after each addition. Whisk for a few more minutes until thick and glossy.

Using a spatula, spread the meringue inside the marked outlines, smoothing out to the edges. Place in the oven, reduce the temperature to 140°C (275°F/Gas 1) and bake for 1 hour, or until the meringues are crisp to touch and will lift off the paper easily. Place on a wire rack to cool completely.

Start making the lemon custard as soon as the meringues go in to the oven, as it must be quite cold before the cream is folded in. Put the egg yolks and sugar in a heavy-based saucepan. Over a low heat, mix until smooth and well combined then add the lemon juice and zest. Continue to stir constantly until the mixture thickens and coats the back of a spoon, about 10 - 15 minutes. Remove from the heat and stir for another minute.

Pour into a bowl and refrigerate until completely cold, or place over a bowl of ice to cool faster. In a separate bowl, whip the cream until firm, then gently fold it in into the cooled lemon custard one spoon at a time, until combined. Refrigerate until needed

Set aside the best meringue disc to be the top. To assemble, place one meringue disc on a piece of baking paper and top it with half of the lemon custard. Do not spread the custard all the way to the edge; when you place the next disc on top, it will spread. Repeat with another layer of meringue and the remaining filling, then top with the final meringue layer. Wrap gently in foil then freeze for several hours or overnight.This can be done several days ahead.

To make the lemon syrup, combine all the syrup ingredients in a small saucepan, stirring over low heat until the sugar dissolves. Simmer, without stirring, for about 5 minutes, or until slightly thickened and tacky. Allow to cool to room temperature.

Remove the lemon meringue from the freezer 30 minutes before serving. Drizzle the lemon syrup over the top.