Boating on the Vierwaldstättersee (literally the “lake of the four forested cantons” but known more typically in English as Lake Lucerne) is quite spectacular, especially on a sunny day.

Blue skies, blue mountains, and sparkly blue water.

So when Sam came home from a work event cruising the lake I expected him to exult the views—but he only had one thing to mention: the Birnenweggen Mousse they had served on the boat.

Birnenweggenfüllung is simply the filling of the traditional Swiss pear bread, Birnenweggen (see my Lucernese version here), and is basically a paste made from dried pears and spices.

Sam, like the good Lözarner he is, loves anything involving this filling (it also features in the Toggenburger Schlorzifladen), and was thrilled to find the recipe for this mousse on the boating company’s website.

The dried pear filling adds a slight graininess and body to the mousse, as well as that wonderful Birnenweggen flavour.

I’ve adjusted the original recipe from the ship’s kitchen, switching white for dark chocolate, removing the gelatin, and scaling it down to serve four (I know the original recipe also says that it serves four, but they must have meant four giants).

2 eggs, separated

1 tbsp sugar

70 g dark (Swiss) chocolate

175 g Birnenweggen filling (see below)

200 ml cream

First you need a bain-marie. Put a large pot of water on medium heat and set a large bowl on top of it (stainless steel works best). Once the water is simmering, turn the heat down to low.

Add the chocolate to the bowl on top. This should melt over low heat (be patient), but if it is taking too long, briefly turn the heat up slightly.

Once it is fully melted, set the bowl aside and let cool.

Whisk the egg yolks and sugar in another bowl, then place this on top of the bain-marie. Keep whisking until the mixture is frothy and lightened in colour, and the sugar has all dissolved. Whisk in the cooled chocolate, then the Birnenweggen filling. Set aside.

Using a large bowl and an electric mixer, start whipping the egg whites until the mixture is stiff.

Whisk one third of the whipped egg whites into the chocolate mixture. Gently fold in the other two thirds with a spatula. 

In the same bowl you used to whip the whites, pour in the cream and whip it to soft peaks. On high speed this should take about a minute.

Fold in the cream, then cover and chill in the fridge for at least two hours before serving. 

• My favourite chocolate to use is Frey 72% dark chocolate from the Migros, but any nice dark chocolate works well.

• Birnenweggen filling can be bought ready-made and is available in Swiss supermarkets and the Landi. If you have dried pears, it is possible to make your own—recipe at the bottom of my post on Birnenweggen, or Betty Bossi has a recipe too, adding other fruits and nuts.