Homemade caramelized onion tart made with red onions, leeks, and other healthy ingredients. This onion pie is called “Zwiebelkuchen” in Germany, and it’s a traditional fall recipe. The dish is vegan, gluten-free, soy-free, easy to make, flavorful, and delicious.
German Onion Tart
There are a couple of things which I love about fall. I enjoy making different pumpkin recipes, but I also love caramelized onion tart and Federweißer! We make Zwiebelkuchen (that’s how it’s called in Germany) quite often, and I absolutely adore it! Federweißer is a very young wine made from grapes, just in case you were wondering. 😀
It was time to publish a vegan onion tart on my blog, and I am really excited to share this recipe with you!
How To Make Caramelized Onion Tart?
This vegan onion tart also contains leeks and bell pepper because both add a great flavor. If you aren’t a fan of either, simply leave it out. You can use a store-bought pie crust, make your own, or try out my vegan and gluten-free pie crust. All ingredients and measurements are below in the recipe card!
STEP 1: Make the “flax eggs” first by adding 2 tbsp of ground flax seeds and 5 tbsp of water to a bowl. Mix with a whisk and set aside for 5 minutes. To make the pie crust, simply add all ingredients to a bowl and mix with a spatula or your hands until the dough sticks together. You can also use a food processor.
STEP 2: Press the dough into a greased/oiled 8-inch tart or pie dish and up the sides, as shown in the below photo. Transfer it into the fridge.
STEP 3: Mix the chickpea flour, cornstarch, spices, and water in a bowl with a whisk. Set aside.
STEP 4: Heat oil in a pan over low/medium heat and add the chopped onion, leeks, and bell pepper. Cook the veggies with a lid for about 15-20 minutes or until lightly caramelized, stirring frequently. Stir in garlic for the last few minutes, and preheat the oven to 390 degrees Fahrenheit (ca. 200 °C).
STEP 5: Add the chickpea flour mixture and stir immediately, as it will thicken very quickly. Also, add plant-based milk and soy sauce.
STEP 6: Let simmer for a few more minutes (the mixture should thicken considerably), then turn off the heat. Pour the filling into the pie crust and smooth it evenly.
STEP 7: You can also add vegan cheese of choice (I used my easy vegan cheese sauce) and pan-fried onion rings on top, but this step is optional.
STEP 8: Bake the onion tart in the oven for about 25-30 minutes, or until nicely caramelized and golden brown.
- Make the pie crust in advance (for example, in the morning or a day ahead) and store it in the fridge.
- Use other veggies for some variation. You can also add zucchini or carrot if you like.
- You can make a couple of mini onion tartlets instead of one regular-sized tart.
- Try making the onion tart in silicone muffin molds without the crust (for a crustless version).
- You can enjoy the onion tart at room temperature or simply reheat it in the oven for a couple of minutes to eat it warm.
How To Store
Store onion tart leftovers covered in the fridge for up to 3-4 days. I haven’t tried freezing the onion tart because we always eat it immediately on the same day. It should freeze well, though.
This Healthy Red Onion Tart Is:
- Bursting with flavor
- Perfect for the holidays (Thanksgiving, Christmas)
- Easy to make
Should you give this caramelized onion tart recipe a try, please leave a comment and rating below, and don’t forget to tag me in your Instagram or Facebook post with @elavegan #elavegan because I would love to see your vegan Zwiebelkuchen remake! 🙂
For more savory holiday dishes, check out the following delicious healthy recipes:
- Vegan Shepherd’s Pie
- Vegan Quiche
- Hearty Vegan Meatloaf
- Vegan Gravy
- Roasted Cauliflower Steaks (Vegan Schnitzel)
- Vegan Green Bean Casserole
- French Onion Soup
- Vegan Pumpkin Soup
- Creamy Mushroom Sauce (Geschnetzeltes)
Caramelized Onion Tart
- 1 cup + 1 tbsp (160 g) (gluten-free) flour (see notes)
- 1/2 cup (60 g) almond flour (see notes)
- 2 tbsp (2 tbsp) ground flax seeds or chia seeds
- 5 tbsp (5 tbsp) water
- 2 1/2 tbsp (30 g) coconut oil softened
- 1/3 tsp (1/3 tsp) sea salt
Onion Tart Filling:
- 3 medium-large (300 g) onions peeled and diced
- 2 medium (200 g) bell peppers diced
- 2 small (130 g) stalks of leek finely chopped
- 3 cloves of (3 cloves) garlic minced
- 3 tbsp (30 g) chickpea flour
- 1 heaped tbsp (10 g) cornstarch or arrowroot flour
- 1/3 cup (80 ml) water or vegetable broth
- 1 tsp (1 tsp) onion powder
- 3/4 tsp (3/4 tsp) sea salt or more/less to taste
- 1/2 tsp (1/2 tsp) paprika
- 1/2 tsp (1/2 tsp) cumin (optional)
- ground black pepper to taste
- 1/2 tbsp (1/2 tbsp) fresh thyme or 1/2 tsp dry
- 1 tbsp (1 tbsp) tamari or soy sauce (GF if needed) or coconut aminos
- 3/4 cup (180 ml) plant-based milk
- 7 oz (200 g) vegan cheese of choice (optional)
- Fried onion rings on top (optional)
- Check the step-by-step process shots and the video above in the blog post.
- Put 2 tbsp ground flax seeds (or ground chia seeds) to a small bowl, add 5 tablespoons of water and mix with a whisk. Set aside for 5 minutes.
- For the pie crust, simply add all ingredients to a bowl and mix with a spatula or your hands until the dough sticks together. You can also use a food processor.
- Press the dough into a greased/oiled 8-inch tart or pie dish and up the sides. Put it into the fridge.
- Mix the chickpea flour, cornstarch, spices, and water or vegetable broth in a bowl with a whisk. Set aside.
- Heat oil in a pan over low/medium heat and add the chopped onion, leek, and bell pepper. Cook the veggies with a lid on for about 15-20 minutes or until lightly caramelized, stirring frequently. Stir in garlic for the last few minutes and preheat the oven to 390 degrees Fahrenheit (ca. 200 °C).
- Add the chickpea flour mixture and stir immediately, as it will thicken very quickly. Also, add plant-based milk and tamari.
- Let simmer for a few more minutes (the mixture should thicken considerably), then turn off the heat. Pour the filling into the pie crust and smooth it evenly.
- You can also add vegan cheese of choice (I used my easy vegan cheese sauce) and pan-fried onion rings on top but this step is optional.
- Bake in the oven for about 25-30 minutes or until nicely browned. Enjoy! Store leftovers covered in the refrigerator for up to 3-4 days.
- Gluten-free flour blend: I used 120 g (3/4 cup) rice flour and 40 g (5 tbsp) tapioca flour. A store-bought gluten-free flour blend (with similar ingredients) should work as well. You can also use regular flour or spelt flour if you're not gluten-free.
- You can use finely ground nuts (e.g. hazelnuts, walnuts, cashews) or even ground sunflower seeds instead of almond flour (ground almonds).
- Recipe serves 8. Nutrition facts are for one serving.
Nutrition information is an estimate and has been calculated automatically
If you are using Pinterest, feel free to pin the following photo:
Made it for Christmas, was easy to follow, recipe tasted absolutely delicious! 10/10 much love from New Zealand. #livinitvegan
So glad you liked it, Matt! 🙂
Happy you like it, Christina. 🙂
thank you. can you tell me what app or website do you use for nutrition facts ?
Hi Jela, I often use Cronometer. 🙂
Noa Van den Daele
Hi Ela! I tried your recipe for dinner tonight and i am amazed… it is one of the best recipes i’ve ever tried, i will definetely make it again. I just used regular flour and roasted bell peppers instead of regular ones, loved it! Thank you so much for this!
You are very welcome, Noa! I am so glad you loved it. Thanks for your kind feedback. 🙂
What other gluten-free flours can be used in place of chickpea flour?
I haven’t tried different flours, so I don’t know. Maybe lentil flour or mung bean flour would work.
Hello! Do you think this can be prepped ahead of time, say a few hours or even the day before? If so, any modifications/ suggestions?
Hey! I think I would just prep the crust in advance, but the filling will thicken very quickly when cooked, so I wouldn’t prep that in advance.
Or you could cook it 5 minutes less, and then reheat it the next day for 10-15 minutes or so. 🙂
Sharon Fiedler Shimanovsky
Hi. I’m going to make this for the first time and am wondering if I bake the pie crust slightly before adding the cooked vegetables (or if I put the vegetables into the raw crust and then bake).
Hi Sharon! I didn’t bake the crust beforehand, however, if you prefer a crispier crust, then you can definitely do it. 🙂
I made this tart using about 1 pound of leeks and 3 carrots instead of peppers due to sensitivity to night-shades. It turned out amazing, which did not come to me as a surprise at all. It was incredibly delicious that even my husband loved it as much as I did and I had to literally hide the tart from him to guarantee a few slices for myself 🙂 One slice of it was also very filling. Thank you for all of your hard work.
Yay, that’s good to hear, Semra! I am so glad you both enjoyed it. 🙂
Thanks for a great recipe – I adapted based on what I had on hand and want to share those changes in case it helps someone – I used regular flour and almond meal (not almond flour) for crust and sunflower oil instead of coconut oil – I added 2 T more oil and 4 T water to get it moist enough.. Used oat flour instead of chickpea flour with onion mixture, everything came out great – many thanks will definitely make again!
Sounds great, Joy! I am glad it turned out delicious. Thanks for sharing your substitutes. 🙂