Homemade caramelized onion tart made with red onions, leek, and other healthy ingredients (and it's gluten-free)

This onion pie is called Zwiebelkuchen in Germany and is a traditional fall recipe. It takes just over an hour to make, but is definitely worth the time!

Vegan Caramelized Onion Tart (German Zwiebelkuchen)

Vegan Caramelized Onion Tart (German Zwiebelkuchen)

  • Duration
  • Cook Time
  • Prep Time
  • 8Servings


Pie Crust

    • 1 cup + 1 tbsp gluten-free flour (*see notes)
    • 1/2 cup almond flour
    • 2 tbsp ground flax seeds
    • 5 tbsp water
    • 2 1/2 tbsp coconut oil softened
    • 1/3 tsp sea salt

Onion Tart Filling

    • 3 medium-large onions peeled and diced
    • 2 medium bell peppers diced
    • 2 small stalks of leek finely chopped
    • 3 cloves of garlic minced
    • 3 tbsp chickpea flour
    • 1 heaped tbsp cornstarch or arrowroot flour
    • 1/3 cup water or vegetable broth
    • 1 tsp onion powder
    • 3/4 tsp sea salt or more/less to taste
    • 1/2 tsp paprika
    • 1/2 tsp cumin
    • ground black pepper to taste
    • 1/2 tbsp fresh thyme or 1/2 tsp dry
    • 1 tbsp soy sauce (gluten-free if needed)
    • 3/4 cup plant-based milk
    • 7 oz vegan cheese of choice (optional)
    • Fried onion rings on top (optional)


  1. Check the step-by-step pictures and the video above in the blog post.
  2. 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.
  3. 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.
  4. Press the dough into a greased/oiled 8-inch tart or pie dish and up the sides. Put it into the fridge.
  5. Mix the chickpea flour, cornstarch, spices, and water or vegetable broth in a bowl with a whisk. Set aside.
  6. 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).
  7. Add the chickpea flour mixture and stir immediately, as it will thicken very quickly. Also, add plant-based milk and soy sauce.
  8. 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.
  9. You can also add vegan cheese of choice and pan-fried onion rings on top but this step is optional.
  10. 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.

This recipe was republished with permission from Ela Vegan. Find the original recipe here

Nutrition Information

  • Serving Size: 8

Related Recipes