Portions: 6 portions Calories: 567kcal |
Are you a fan of French onion soup and savory tarts? If so, then you'll absolutely love this gruyere cheese and caramelized onion tart: a rustic crust filled with creamy, gently sweet caramelized onions, and topped with abundant melted strong cheese.
By - Revised . Original Oct 1, 2013.
Gruyere and Caramelized Onion Tart Recipe.
Why we ❤️ it
- If you enjoy French onion soup, you will love this rustic and easy-to-make tart.
- The result is a crispy crust filled with a creamy and smooth onion filling, with the sweet flavours of slow and gentle caramelisation, finished with the contrasting taste of strong cheeses.
- This will be a new favorite on your list of tart recipes, perfect for your dinner or brunch.
Gruyere and Caramelized Onion Tart Recipe
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Utensils and tools
- Pie weights (or dry beans, or any dry pulses)
Ingredients
FOR THE CRUST
- 1¾ cup whole-wheat flour
- ¾ teaspoon salt
- 1 teaspoon baking soda
- ⅓ cup unsalted butter, melted
- 1 egg
- ½ cup cold water, may not need all
FOR THE FILLING
- ¼ cup olive oil
- 3 pounds white onion, [1.4 kilogram], halved and sliced thinly
- ½ teaspoon fresh thyme leaves, or dry if you don't have fresh
- ½ cup cooking sherry
- 1 tablespoon garlic salt, (see notes)
- 1 teaspoon black pepper, freshly-cracked, or ground
- ½ teaspoon nutmeg, freshly grated
- 2 tablespoons all-purpose flour
- 1 cup grated Gruyère cheese
- ½ cup shredded sharp cheddar
Preparation
1. Mixing ingredients for the crust
In a mixing bowl, mix flour, salt, and baking soda. Pour the mix into the food processor.Pour in melted butter and egg, and pulse to incorporate. Midway stop and scrape the sides with a spatula moving the flour from the sides to the middle. If the dough is too dry, add cold water by the tablespoon until the dough just forms a ball but is not soggy or sticky.
2. Making the dough
- Pour onto the counter and knead the dough lightly until it is smooth (about 1 minute).Wrap in plastic film and let it rest at room temperature for at least 10 minutes.
3. Caramelizing the onions
- Heat the oil over medium-low heat in the skillet. Add the onions and thyme and stir until the onions are coated with oil. Cover and simmer over for 5 minutes, stirring often.Add the sherry, and simmer until the sherry has mostly evaporated. Cover and simmer over low heat for another 25-30 minutes, or until the onions have turned caramel brown and are very tender.Season with garlic salt, pepper, and nutmeg.
4. Add the flour
Increase heat to medium-high heat and add flour, sprinkling, and mixing until all the onions are lightly coated with flour. Remove from the heat.Let it rest until the onion mixture has cooled to room temperature.
5. Preheating the oven
Heat oven to 350 ºF [175 ºC].
6. Forming the crust
- Roll out the dough with a rolling pin until you have a circle big enough to cover the bottom and sides of the tart pan.Cover the tart pan with the dough and tidy up the sides using any excess dough. Poke a few holes in the bottom with a fork. Line the bottom with a circle of parchment paper, and place the pie weights or dry beans on the parchment paper.
7. Baking the pie
- Bake the pie crust in the preheated oven for 15 minutes. Remove from the oven.Fill the pie crust with the onion mixture, and top with the cheeses.
8. Melting the cheese
- Return to the oven and bake until the cheese is bubbly and golden brown.Remove from the oven and serve hot.
Utensils and tools
- Mixing bowl
Food processor - Plastic film
- 12-inch skillet with lid [25 centimeters]
- 10-inch tart pan [20 centimeters]
- Parchment paper
- Pie weights (or dry beans, or any dry pulses)
Top tips
- Garlic: If you don't have garlic salt, mix ½ tablespoon of regular with ½ tablespoon of garlic powder.
- Dough: Whole wheat dough is very fragile and not elastic like regular dough; I've found that the best way to spread it is between two plastic film pieces. There's going to be some patching too. Don't worry too much; that's why I called it "rustic."
- Caramelizing onion: If you want the trick on how to caramelize onions: it takes time. Do not try to rush it, do not try to increase the heat to cook it faster, and do not add sugar to it.
- With puff pastry: You can make this French onion soup-inspired onion tart with puff pastry for a different and entirely marvelous variation. Instead of making the crust as directed, revert the order of the ingredientes by placing the onions in the pan, followed by the cheese, and topped with a circle of puff pastry, which you'll then bake until the puff pastry is baked.
- Vegan or vegetarian onion tart: Use your favorite cheese substitute (I've found some pretty good vegan ones), or skip the cheese entirely. The onion is sublime in itself. Use your preferred butter substitute for the crust. I have done it with vegetable oil too.
Serving suggestions
This onion tart goes great with your favorite green salad if you serve it for dinner or brunch.
You can also try this leek and squash quiche if you're looking for another similar casserole for your meal.
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Nutrition
Calories: 567kcal | Carbohydrates: 50g | Protein: 17g | Fat: 33g | Saturated Fat: 9g | Cholesterol: 36mg | Sodium: 1788mg | Potassium: 526mg | Fiber: 8g | Sugar: 11g | Vitamin A: 335IU | Vitamin C: 16.7mg | Calcium: 379mg | Iron: 2.1mg
Nutritional information is calculated automatically based on ingredients listed. Please consult your doctor if you need precise nutrition information.
Learn how to make this gruyere and caramelized onion tart. The result is a crispy crust filled with a creamy, gentle onion, topped with sharp cheeses.
Will be trying your zucchini boat recipe tonight! Lost my recipe, but it is very similar.
I love your recipes! 😀
I absolutely love caramelized onion and how wonderful to find out that we can make a savory tart with it! This is such a nice treat for me (even it's not sweet). 🙂
Wouldn't that be such fun! It would be very difficult for me to get together with most of my fellow bloggers because I live so far away but the idea is a great one. I used to love onion tarts and especially with a good load of cheese and the… Read more »
Your photos are so beautiful (love the dishware and utensils) and this tart looks exceptional. Nothing quite like caramelized onion. What a delight!
Thanks, Kelly. It was every bit as good as it looks. I made three in a week, you know, just to make sure. 🙂