1) Preheat oven to 180 degrees C/Gas 4.
2) In a bowl whisk egg yolks and 100g sugar until it is a pale yellow, set aside.
3) In a medium saucepan heat double cream, over low heat, to just a boil. Slowly add cream to yolks, whisking constantly to avoid curdling. Transfer yolk mixture back to saucepan. Cook until custard thickens and coats the back of a spoon, then add vanilla and whiskey. Keep custard over low heat to keep warm, but do not allow eggs to curdle.
4) In a clean medium bowl whisk the egg whites, remaining 15g of sugar, cream of tartar and salt until stiff peaks form.
5) Drop heaped spoonfuls of the meringue onto a baking paper lined baking tray. Bake 8 minutes, or until peaks are golden.
6) To assemble, divide custard into 4 shallow bowls. Top each with a meringue peak, sprinkle with berries and icing sugar.
7) Serve immediately.