Name: A Delicious Classic Onion Tart Recipe
Prep time: 30 min
Cook time: 50 min
Total time: 1 h 20 min
Yield: 8
Ingredients: 200 g all-purpose flour; 100 g cold unsalted butter (cut into cubes); 1 egg; pinch of salt; 1-2 tbsp cold water; 3-4 large onions (about 500 g); 30 g unsalted butter; 100 ml heavy cream (20-30%); 2 eggs; 100 g hard cheese (such as Gruyère, Parmesan, or Cheddar), grated; Salt and pepper to taste; A pinch of nutmeg (optional)

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Onion tarts have a special place in my heart because they combine simplicity with incredible flavor. Whether you’re looking for an appetizer to impress guests or a comforting dish to enjoy at home, this tart fits the bill. The process of caramelizing onions until they reach that perfect golden sweetness is therapeutic, and the creamy custard adds a velvety texture that makes each bite unforgettable. It’s a wonderful balance of savory and sweet, and I love how versatile it is – perfect for any occasion.

This tart is a great way to enjoy the depth of flavor that onions can bring to a dish. With its buttery, flaky crust and rich, caramelized onion filling, it’s a dish that feels both comforting and elegant. It’s easy to prepare yet feels special enough to serve on your next gathering or family dinner. It’s also a fantastic choice for any season, offering warmth and satisfaction, no matter the time of year.

What I love most about making this onion tart is how adaptable it is. You can easily tweak the recipe to suit your taste – whether by adding a sprinkle of cheese, a touch of herbs, or a dash of balsamic vinegar to enhance the flavor of the onions. It’s a dish that invites creativity while still being rooted in its classic flavors. I hope you enjoy making and sharing this tart as much as I do!

Table of Contents

Ingredients

For the crust (shortcrust pastry):

200 g all-purpose flour: This forms the base of the tart, providing structure and texture for the flaky crust.
100 g cold unsalted butter (cut into cubes): The cold butter is key to achieving a crisp, buttery crust that melts in your mouth.
1 egg: Helps bind the dough together, giving it richness and structure.
A pinch of salt: Adds balance to the dough, enhancing the flavors of the crust.
1-2 tbsp cold water: This helps bring the dough together without making it too sticky, ensuring a smooth, easy-to-work pastry.

For the filling:

3-4 large onions (about 500 g): These are the star of the dish, caramelized to bring out their natural sweetness and depth of flavor.
30 g unsalted butter: Used to sauté the onions, giving them a rich, buttery flavor as they caramelize.
100 ml heavy cream (20-30%): Adds a luscious creaminess to the filling, creating a smooth and indulgent texture.
2 eggs: These help set the filling, creating a custard-like texture that holds everything together.
100 g hard cheese (such as Gruyère, Parmesan, or Cheddar), grated: Adds a savory, melty richness to the filling, enhancing the tart’s flavor.
Salt and pepper to taste: Season the filling to bring out the natural sweetness of the onions and the richness of the cream.
A pinch of nutmeg (optional): Adds a warm, subtle spice that complements the savory flavors of the tart.

Recipe Instructions

You can find a printable recipe card at the bottom of this post.

1. In a large bowl, mix the flour, salt, and butter, rubbing the mixture with your fingers until it resembles fine breadcrumbs.

2. Add the egg and cold water. Knead the dough until smooth.

3. Shape the dough into a ball, wrap it in cling film, and chill in the refrigerator for 30 minutes.

4. Thinly slice the onions into half-rings.

5. Melt the butter over medium heat and sauté the onions until soft and caramelized (about 20 minutes). Stir frequently to avoid burning.

6. In a bowl, whisk together the eggs and cream. Add grated cheese, salt, pepper, and nutmeg. Mix well.

7. Roll out the chilled dough and line a tart pan (about 23 cm in diameter), forming the edges. Prick the base with a fork.

8. Spread the caramelized onions over the crust and pour the cheese and cream mixture on top.

9. Bake at 180°C (350°F) for 25-30 minutes, until the filling is golden and set.

10. Let the tart cool slightly before slicing. It tastes great both warm and cold.

Frequently Asked Questions

1. Can I make the crust ahead of time?
Yes! The shortcrust pastry can be prepared in advance and stored in the fridge for up to 2 days or frozen for up to a month. Just roll it out when you’re ready to bake.

2. Can I use store-bought pastry for this recipe?
Absolutely! If you’re short on time or prefer convenience, you can use store-bought shortcrust pastry. Just be sure to follow the package instructions for blind baking.

3. Can I substitute the heavy cream in the filling?
If you prefer a lighter option, you can substitute the heavy cream with half-and-half or milk, but the texture and richness will be different. For a dairy-free version, try using coconut cream or a plant-based cream alternative.

4. Can I add other vegetables to the filling?
Yes! You can mix in other vegetables like leeks, shallots, or spinach. Just be sure to cook them thoroughly to remove any excess moisture before adding them to the filling.

5. How do I store leftover onion tart?
Leftover onion tart can be stored in an airtight container in the fridge for up to 3 days. Reheat in the oven for the best texture, or enjoy it cold as a savory snack.

6. Can I freeze the onion tart?
Yes, you can freeze the tart before or after baking. If freezing before baking, assemble the tart, then wrap it tightly in plastic wrap and foil. Bake directly from frozen, adding extra time to the cooking process.

7. Can I make this recipe vegetarian?
Yes! This onion tart is already vegetarian, but if you’d like to add extra flavor, you could consider adding herbs or a sprinkle of crumbled feta or goat cheese.

8. Can I use a different type of cheese?
Certainly! While Gruyère, Parmesan, or Cheddar work wonderfully in this recipe, feel free to experiment with other hard cheeses like Comté, Gouda, or Swiss for a different twist.

Yield: 8