One of my favorite German fall dishes is the onion tart. There are about a million variations of this dish. I’m sure one German could have a long discussion with another German about the appropriate height of the filling and whether to add cheese and if so, which cheese. My recipe is based on my dad’s take on the dish. It does not include cheese and I would never even dare think of committing such an act of blasphemy. This dish is already very heavy – consider yourself warned! – adding cheese would just tip a fine comfort food into the junk food department.
My dad’s onion cake always included the onions roughly chopped, but I choose to cut them into slices as I think this is more elgant. For me true onion cake includes a strong note of caraway, so I add both caraway seeds and ground caraway just to make sure I obtain one. Aside from being somewhat time-intensive and costing you a couple of tears and smelly hands from all the onion cutting and frying, making onion tart, or Zwiebelkuchen as we call it, is totally worth the effort. The crust is crumbly and buttery, so I usually devour the filling first and then eat the crust as a treat toward the end!
It’s a great dish to serve for guests, perhaps along with a light salad with a sweet and spicy dressing and some nuts. Don’t forget to offer a cold glass of new white wine (which in Germany we call Federweisser), too! The onion tart will fill your house with a very beautiful smell of roasted onions and a crispy crust.
Zwiebelkuchen (Onion Tart)
150g gluten-free flour mix
2 tbsp new white wine (or regular dry white wine if that’s the only thing you have in the house)
In a bowl mix together all the ingredients until you obtain a somewhat firm dough. Roll into a ball and cover with plastic wrap entirely and place into your fridge. This can be prepared a day ahead of time.
Butter and vegetable oil
200g sour cream (in Germany, Saure Sahne has 10 percent fat, you can also do this with yoghurt or quark if you want a lighter version, but do consider this carefully as you’re losing a lot of the taste, too)
1 tbsp gluten-free flour (or cornstarch)
salt, pepper, sweet red pepper, caraway seeds and ground caraway to taste
Peel the onions and cut into slices of half a centimeter. Place onions into a warm pan in which you have already heated a tablespoon of vegetable oil. Fry the onions until tender, add a teaspoon of butter toward the end to help the onions obtain a nice brown color. Don’t burn them though, so do stir every once in a while. Turn pan off when onions are tender. You can prepare the onions a day ahead, too.
Heat your oven to 220 °C.
Take the dough out of the oven, place into a small round cake dish that you have lined with parchment paper. Place the dough into the middle and begin spreading dough evenly throughout baking dish and along the sides, ensuring that crust alongside the baking dish is symmetrical and even in height and width. Poke holes into the crust with a fork evenly throughout dish (on the bottom and on the sides), then place crust into the hot oven for about ten minutes.
In a bowl, combine, the sour cream and the eggs evenly, add the cornstarch and repeat. Add the onions (somewhat cooled, you don’t want them to solidify the eggs) and mix well. Add the salt (about a teaspoon), the pepper (a generous dash), the caraway seeds (a teaspoon) and the ground caraway (half a teaspoon) to taste.
Take cake dish out of the oven using oven mits and place it somewhere safe. Carefully distribute the onion-sour-cream-mix into the pre-baked crust, and place your onion tart into the oven until done, about 45 minutes. The filling of the onion tart should be solid and golden brown on top.
If the top of your onion tart is threatening to burn, place a bit of aluminum foil over it twenty minutes through baking and uncover again for the last ten minutes.