Caramelized Onion Tart Recipe (2024)

This is an easy-to-make Caramelized Onion Tart that uses a baked, ready-to-use short pastry crust. The happy combination of caramelized onions with the Cheddar and Parmesan cheese will bring your family around the table for a delicious brunch, lunch, or dinner.

Is this a tart, or shall we call it Caramelized Onion Quiche?

Good question and I am glad you asked it. By definition, a tart can be savory or sweet, but a quiche is always savory, so technically, we could call a quiche to be a savory tart.

I think it all depends on where the recipe comes from and what people are used to calling different dishes.

I called my recipe a tart, but you can call it a quiche if this is how you prefer. I don't think it really matters as long as you get in the kitchen and make the recipe.

Why you should make this recipe

1. The recipe is easy to make and very delicious.
2. It uses an already baked short pastry crust that you can buy in the store if you choose not to make the crust from scratch.
3. Cooking and caramelizing onions in butter (yum) is a wonderful experience. I personally love caramelized onions and use them for different recipes, like this Authentic Mexican Bistec Encebollado- Steak And Onion. I also cook tons of onions when I make Romanian Vegetable Spread- Zacusca.
4. Savory tarts make elegant appetizers for a dinner party, and they’re perfect for everyday eating. Serve them with a salad, and you are in for a treat.
5. This recipe is good served hot, at room temperature, or cold.

Ingredients

First of all, you will need a ready-baked shortbread crust. You can either buy it, or you can make it from scratch. See the recipe card at the bottom of this article that gives you also an easy recipe for the crust if you choose to make it from scratch.

• Heavy cream- is a good choice for the recipe, as milk or half-and-half would be too thin for the custard. You want the tart to have an unctuous texture, and fat helps a lot in this case.
• Lots of onions- You might need somewhere between 6-8 medium onions. See the notes in the recipe.
• Cheddar Cheese- I like Cheddar, but if you have Gruyere, you can replace the Cheddar with it, no biggie. I saw recipes out there that use all kinds of cheese, from Feta to goat cheese and Gorgonzola.
• Parmesan Cheese- We will use this cheese to sprinkle the top of the tart with it. It adds saltiness to the final product.
• Other ingredients- Unsalted butter, eggs, salt, and pepper

What kind of special tools do I need for this recipe?

• A good knife(affiliate link) for slicing the onions- nothing like a good knife that cuts. I have these knives from Amazon(affiliate link) and like them a lot. They are not very expensive, but they are sharp and stay sharp for a long time.
• Measuring cups- You need to measure the onions, the heavy cream, and the rest of the ingredients.
• Kitchen scale(affiliate link)- If you really want to make your life easier in the kitchen and be able to measure ingredients for both American and European recipes, you definitely need a kitchen scale.
• A heavy bottom skillet(affiliate link)- If you click on the affiliate link, you will understand what I am talking about. I love Lodge Manufacturing Carbon Steel Skillets. They are lighter than their sisters, the Cast Iron Skillets, but heavy enough to do a great job on caramelizing foods.
• Baking sheet(affiliate link)- We need a baking sheet for placing the tart on it and bake it.
• Serving spatulas(affiliate link)

How To Make

Step 1. The Crust

You will need an already-baked pie shell. If you buy it, make sure it is a short-crust pastry and not the one made with Graham crackers. The Graham crackers crusts are made for sweet pies and tarts, not for savory ones.

If you choose to make the crust from scratch, the recipe is on the recipe card. Don't be nervous. It is a straightforward recipe that doesn't require a lot of time to make.

The recipe gives you the ingredients for a double-crust pie/tart, so use only half of it. You can freeze the other half and use it later for another recipe.

Step 2. Cook the onions

• Slice them thinly. This is basically the most consuming part of the entire recipe. You will need between 6-8 medium onions sliced nice and thin.

• Melt the butter in a heavy-based frying pan over medium heat. Add the onions and cook, frequently stirring to avoid burning, for 30 minutes or until well-browned and caramelized. Remove the onions from the pan and set them aside.

Step 3. Preheat the oven to 375F/190C.

Step 4. Prepare the custard.

Beat the eggs in a large bowl. Stir in the heavy cream and season to taste with salt and pepper. Add the Cheddar cheese and mix well. Stir in the cooked onions.

Step 5. Put the tart together.

Pour the egg and onion mixture into the baked pastry case and sprinkle with the Parmesan cheese.

Step 6. Bake.

Place tart pan on a baking sheet and bake in the preheated oven for 15-20 minutes, until the filling has set and is beginning to brown.

Remove from the oven and leave to rest for at least 10 minutes. Cut the tart into slices and serve hot or at room temperature.

Common questions

Tart/quiche suggestions

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