Step by step recipe:

1. 30 min.
   Prepare 350 g Lemon Confectioner's Custard.
   
   When done, cover the custard, stand the pan in cold water and leave to cool.
   
   Set aside.
2. 10 min.
   Peel 6 apples and cut into small pieces.
3. 10 min.
   Pour 30 g Clarified butter into a large frying pan on high heat. When hot, add the apples and 2 tablespoons caster sugar.
   
   Sauté the apples until they soften, but without browning.
   
   You can flambé them with 3 tablespoons Calvados (apple liqueur) if you wish, but this is not essential.
   
   Set aside.
4. 4 min.
   Beat 90 g egg white to the "stiff peak" stage, adding 75 g caster sugar towards the end while still beating, to make the raw meringue mix.
5. 3 min.
   Take a little of the meringue and add this to the lemon custard.
   
   Mix in with a soft spatula.
6. 4 min.
   Then add this mixture to the rest of the meringue and fold in gently until evenly mixed and light.
   
   Note:Mixing in 2 stages like this helps to combine the two different textures of the meringue and confectioner's custard.
7. 3 min.
   Add the apple pieces and mix again gently.
   
   Preheat the oven to 390°F (200°C).
8. 3 min.
   Put the mixture into a buttered gratin dish and bake for about 10 minutes.
9. 10 min.
   After 5 minutes, sprinkle the top with caster sugar and change your oven setting to "grill" (broiler) to brown the top (if your grill is separate, leave the dish in the oven for a couple of minutes longer, then brown briefly under the grill).