The lovely Swiss city of Schaffhausen lies along the northern border with Germany, next to the rushing Rhine and plenty of rolling vineyards. A crisp white wine is the perfect accompaniment for their most famous dish too, the Bölletünne.

The name is straightforward, if you understand the Schaffhauser dialect: Bölle means onion, and Tünne means Wähe (Switzerland’s favourite sweet or savoury tart).

It’s not dissimilar to the Zibelechueche, Bern’s famous onion tart, though the variety from Schaffhausen includes a sprinkling of bacon.

There are lots of recipes for this beloved specialty online, from Betty Bossi to one of my favourite independent Swiss food bloggers, lamiacucina. In general the recipes don’t vary too much (except for Betty Bossi’s yeated dough), with similar amounts of onions and bacon filling.

I stuck to my tried and tested Wähe dough and Guss (custardy filling), and made sure to go heavy on the onions because that’s the name of the tart.

My favourite pairing is with Klett, a sparkling white that also comes form Schaffhausen (and is currently on sale at the Coop!).

Dough:

200 g flour

pinch of salt

80 g butter, cold

125 ml water, cold

Filling:

100 g bacon, diced

600 g onions, chopped

200 ml milk

2 eggs

nutmeg, salt and pepper

2 tbsp breadcrumbs

For the dough:

In a large bowl, whisk together the flour and salt.

Add the cold butter in pieces and rub into the flour mixture with your fingers until you have small flakes.

Make a well in the middle of the flour and add the water. Mix this gently until a dough forms. Try not to overwork the dough or it will become tough.

Press the dough into a disc, wrap with plastic, and let cool in the fridge for about an hour.

Roll out your dough and line a 26 cm (10 inch) round tart pan. Keep the tart shell cool (preferably in the freezer) until you have the filling ready. 

Filling:

In a large pan, fry the bacon over medium high heat until the pan gets a little greasy. Lower the heat and add the onion, cooking until soft and translucent, for about 10 minutes.

Remove from heat and let cool in the pan, or transfer to another bowl to cool.

Preheat oven to 200 C / 400 F / gas mark 6, bottom heat.

Whisk together the eggs, milk, and seasonings.

Get your prepared tart shell, sprinkle over the breadcrumbs, then add the onion mixture.

Pour the egg mixture over top.

Bake in the bottom part of the oven for about 35-40 minutes, or until the tart is nicely browned.

• To save time, you can use store-bought dough like Kuchenteig / pâte brisée / pasta per crostate to line your pan.

• Don’t omit the breadcrumbs, they help absorb additional liquid and prevent a soggy bottom.