German Onion Pie (Zwiebelkuchen)

Warm, rustic, and bursting with flavor, German Onion Pie—known as Zwiebelkuchen—is a cherished dish in Southern Germany, especially during the harvest season. The rich scent of caramelized onions and smoky pork wafting through the kitchen signals comfort and tradition. Wrapped in a tender, yeast-raised crust and filled with a velvety custard infused with savory ingredients, this pie is perfect for cool evenings and festive gatherings alike. Enjoyed with a glass of new wine, it’s a culinary embrace from the heart of Germany.

Ingredients

For the dough:

2 ½ cups (320 g) all-purpose flour
1 packet (7 g) active dry yeast
½ tsp sugar
¾ cup (180 ml) warm milk
2 tbsp olive oil or melted butter
½ tsp salt

For the filling:

4 large onions (approx. 800 g), thinly sliced
1 tbsp butter
140 g (about 5 oz) of finely chopped smoked pork belly or pancetta
1 tsp caraway seeds (optional but traditional)
¾ cup (180 ml) of your choice: tangy sour cream to add a zesty edge, or rich crème fraîche for a smoother, creamier depth
¾ cup (180 ml) heavy cream
2 large eggs
Salt and freshly ground black pepper
Pinch of nutmeg (optional)

Instructions

Step 1: Make the dough

In a small bowl, dissolve yeast and sugar in warm milk. Allow the mixture to rest for about 10 minutes, or until it becomes bubbly and frothy on the surface.
In a large bowl, mix flour and salt. Add the yeast mixture and oil. Knead the mixture by hand or with a dough hook until it transforms into a soft, elastic, and smooth dough—this should take about 8 to 10 minutes.
Drape the bowl with a clean kitchen towel or seal it with plastic wrap, then set it in a cozy, draft-free area of your kitchen to encourage a steady and even rise. Let the dough rise undisturbed for around 1 hour, or until it has visibly puffed up to twice its original size, signaling it’s ready for the next step.

Step 2: Prepare the filling

Heat the butter in a spacious skillet set over medium heat. Once melted and sizzling, add the diced smoked pork and cook, stirring occasionally, until it turns golden brown and develops a deliciously crisp texture.
Add sliced onions and cook slowly, stirring often, for 15–20 minutes until soft and translucent (not browned).
Stir in caraway seeds if using. Let the mixture cool slightly.
In a bowl, whisk eggs, sour cream, and heavy cream. Season with salt, pepper, and nutmeg.

Step 3: Assemble the pie

Preheat oven to 375°F (190°C).
Roll out the dough and press into a greased 10-inch (25 cm) tart or pie pan, forming a slight edge.
Evenly distribute the savory onion and crisped smoked pork mixture across the surface of the dough, ensuring full coverage for balanced flavor in every bite. Pour the custard over the top.
Slide the pie into the preheated oven and let it bake for 35 to 40 minutes, until the custard sets into a silky texture and the top takes on a delicate, golden finish, lightly crisped and irresistibly fragrant—your Zwiebelkuchen is now perfectly baked.

Alternative Tips & Variations:

Vegetarian Option: Omit the smoked pork and replace it with a mix of sautéed mushrooms or caramelized leeks for a deep umami flavor.
Cheese Twist: Add a handful of grated Emmental or Gruyère cheese to the custard mixture for extra richness.
Crust Alternative: For a quicker version, use pre-made shortcrust pastry, though the yeast dough adds authenticity.
Spice It Up: Elevate the flavor by incorporating a pinch of smoky paprika, ground white pepper, or a touch of fresh thyme or rosemary into the filling for a fragrant and savory layer of depth.
Make Ahead: This pie can be assembled in advance and refrigerated, then baked just before serving.
Serve Smart: Pairs wonderfully with crisp white wines or a light German beer for a full culinary experience.

Conclusion:

Whether you’re enjoying it at a festive gathering or savoring a cozy night in, this German Onion Pie brings comfort and flavor to the table. Let its warmth and richness become a cherished addition to your recipe collection. Guten Appetit!