The German Files: Onion Tart

Continuing my journey back to my childhood in Germany, I am sharing today a recipe that my mum never cooked but that I loved since I entered a wine bar for the first time. You will find onion tarts especially in wine regions in Germany and France – with good reason as it goes so well with wine (and beer for that matter). It is easy to make, doesn’t break the bank and tastes utterly delicious. I haven’t made it in ages so I took the opportunity the other day and invited my friend Agnes over to feed her my version of onion tart.

The secret to a good onion tart is slow-cooked onions but not caramelising them. You want the sweetness of the onion to come out but you don’t want to brown them. The next step is to get the right egg/cream/milk ratio perfect. You want the tart to set but not to taste eggy – you want the onion flavour to come through without interference from the eggs.

I add French mustard to the egg mix and salt but no pepper. Depending on the area you are in, bacon bits might be added but I don’t like the flavour of the bacon overpowering the sweetness of the onions. But feel free to add bacon if you like. Even better, try to get your hands on some smoked speck.

Now, the pastry. You can use shop-bought shortcrust pastry or make it yourself. I always make my own, so I am giving you my recipe but there would be nothing wrong with the shop-bought ones.

In France, you will be served a nice white Alsace wine while in Germany it might be a nice Riesling.

Note: You can also create individual tarts and serve as a starter

Onion Tart

For the pastry:

• 300g plain flour
• 1/2 tsp salt
• 150g butter
• 1 egg
• cold water

For the filling:

• 3 brown onions, thinly sliced
• Olive oil
• 2 eggs
• 150ml cream
• 1-2tsp Dijon mustard
• Herbs like chives or parsley, finely chopped
• salt to taste

In a bowl, combine salt and flour, then rub the butter into the flour until it resembles breadcrumbs. Add the egg and using a knife, start cutting the egg through the flour until the mix comes together. Only if the mix seems to be too dry to come together, add a small amount of cold water (start with a few drops) and keep cutting with the knife through the mix. When it starts coming together, you can use your hands to bring the dough into a ball. Try to handle the dough not too much. Wrap in clingfilm and chill for at least 30 minutes. 

In the meantime, prepare the onion mix. In a frying pan, heat the olive oil over a medium heat and add the onions. Cook over medium heat until onions are translucent and soft – this can take 20 minutes, so please be patient. It is worth the effort. 

Preheat the oven to 160C.

Roll the chilled pastry out to fit a 20cm tart dish. Prick the bottom a few times (make sure that there are no gaps in the pastry) and blind bake for about 10 minutes.

In the meantime, mix the eggs, cream, mustard, most of the herbs and seasoning. Arrange the onions in the halfbaked pastry bottom and carefully pour the egg mixture.

over the onions, make sure that the mix doesn’t overflow. Place in the middle of the oven and bake for about 20-30 minutes until the egg mix has just set.

Remove the tart from the oven and leave to cool for a bit. You can serve the tart either hot or at room temperature. Sprinkle with the rest of the herbs and serve with a fresh green salad.

Bon Appetite xx