1. Warm the milk until lukewarm. Add the yeast to the milk and stir until dissolved. Let sit for about 5 minutes. Melt the butter for the dough and let cool down.

2. Mix the flour, salt, and sugar in a large bowl. Add the yeast milk and melted butter and knead everything for about 5-6 minutes to get a nice and smooth dough. Cover the bowl and let the dough rise in a warm place for about 45 minutes.

3. While the dough is rising, prepare the filling. Peel the onions and garlic, cut the onions into rings and finely dice the garlic.

4. Add some oil to a large pot and heat up. Add the bacon and fry briefly to render out some of the fat. Add the onions and garlic and sauté for about 10 minutes (reduce the heat a bit). The onions should be soft and lightly browned. Season with caraway seeds, salt, and pepper, then remove from the heat and let cool down.

5. Preheat the oven to 200°C (390°F). Lightly grease a 10 inches (26cm) pie dish or springform tin and set aside. Roll out the dough on a lightly floured surface a bit larger than the dish/pan, transfer and press to the bottom and sides. The edge should be about 1.6 inches (4cm) high. Place a piece of baking paper on top of the dough and top with baking beans. Pre-bake the dough for about 8 minutes.

6. Add the sour cream, eggs, and cheese to the onions and mix well. Remove the baking dish from the oven, remove the baking paper and baking beans, and pour in the filling. Bake the onion pie for about 35-40 minutes – the filling should have set and the edges should be nicely browned. Take out of the oven and let cool down a bit. The Zwiebelkuchen tastes best while still a bit warm.