This German onion tart (Zwiebelkuchen) is a savory German classic made with a flaky crust, caramelized onions, and a creamy filling with speck or pancetta. It’s an easy, authentic German recipe perfect for lunch or dinner.
In the bowl of a stand mixer fitted with a dough hook, combine the flour, salt, cold butter cubes, egg, and cold water. Mix on low speed until the dough just comes together. Small bits of butter should remain visible for a flaky crust. Shape into a ball, wrap, and refrigerate for 30 minutes.
Roll and chill:
On a lightly floured surface, roll the chilled dough into a circle large enough for your tart or quiche pan. Press it into the pan, trim excess, and patch as needed. Chill again for at least 30 minutes (or freeze for 15–20 minutes). Prick the crust with a fork to prevent air bubbles from forming. See picture below.
Prepare the filling:
Sauté the speck or pancetta in a large pan. Add the sliced onions and cook until soft and lightly caramelized. Stir in the caraway seeds (if using). Let the mixture cool slightly.
In a bowl, whisk together the eggs and sour cream. Add the onion mixture and shredded cheese, then season with salt and pepper.
Assemble and bake:
Preheat the oven to 400°F (200°C). Pour the filling into the chilled crust and spread evenly. Bake for about 35-40minutes, or until the filling is set and the top is golden.
For the best results, I highly recommend using a kitchen scale—this will give you the most accurate and consistent outcome.
Make sure to chill your dough before baking, as this helps prevent the crust from shrinking in the oven.
When rolling out the dough, try not to use too much extra flour, and avoid overworking it, as that can also cause the crust to shrink and become less tender.
