You could make the pastry case and lemon filling in advance then whip up the meringue just before baking this classic dessert. Preheat the oven to 200C/400F/Gas 6. Grease a 20cm/8in fluted flan tin.
Cook the mixture for another minute, then pour it into the flan case. FOR THE TOPPING: Whisk the egg whites until they stiffen. This should take 5-7 minutes. Add the remaining Stevia, keep whisking, ...