Name: Caramelized Onion and Cheese Tarts
Prep time: 15 min
Cook time: 1 h
Total time: 1 h 15 min
Cuisine: French
Ingredients: 3 large yellow onions; 2 tablespoons olive oil; 1 tablespoon unsalted butter; 1 teaspoon granulated sugar; 1/2 teaspoon balsamic vinegar; 1/2 teaspoon dried thyme (or 1 teaspoon fresh thyme leaves); Salt and freshly ground black pepper to taste; 8 ounces cream cheese, softened; 4 ounces Gruyère cheese, grated; 2 ounces Parmesan cheese, grated; 1 large egg; 1/4 cup heavy cream or crème fraîche; Pinch of nutmeg (optional); 1 box (14.1 ounces) refrigerated pie crusts (or homemade pie crust); Fresh thyme sprigs for garnish; Balsamic glaze for drizzling

why make this recipe

Caramelized Onion and Cheese Tarts are an absolute delight! This recipe combines the sweet, rich flavor of caramelized onions with creamy cheeses in a flaky crust. Perfect for appetizers or a light meal, these tarts are easy to share and even easier to make. Plus, they are a fantastic way to impress family and friends with your baking skills!

🧰 Kitchen tools commonly used in similar recipes

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how to make Caramelized Onion and Cheese Tarts

Ingredients:

3 large yellow onions: Yellow onions are the workhorse of caramelization. Their balanced sweetness and savory depth make them ideal for this process. Look for firm onions without blemishes. About 2 pounds in total is a good starting point.
2 tablespoons olive oil: Use a good quality extra virgin olive oil. It adds flavor and helps the onions caramelize beautifully without burning. You can also use butter or a combination of butter and olive oil for a richer flavor.
1 tablespoon butter (unsalted): Butter adds richness and helps in the browning process of the onions. Unsalted butter allows you to control the overall saltiness of the dish.
1 teaspoon granulated sugar: A touch of sugar assists in the caramelization process, enhancing the natural sweetness of the onions and promoting browning. You can also use brown sugar for a slightly molasses-like note.
1/2 teaspoon balsamic vinegar: Balsamic vinegar adds a crucial layer of acidity and depth to the caramelized onions, cutting through the sweetness and adding complexity. Use a good quality balsamic for the best flavor.
1/2 teaspoon dried thyme (or 1 teaspoon fresh thyme leaves): Thyme provides a subtle earthy and herbaceous note that complements the sweetness of the onions and the richness of the cheese. Fresh thyme is always preferable if available, but dried thyme works well too.
Salt and freshly ground black pepper: Seasoning is key! Salt enhances the flavors of the onions and balances the sweetness. Freshly ground black pepper adds a touch of spice and complexity. Adjust the amount of salt and pepper to your taste throughout the caramelization process.
8 ounces cream cheese, softened: Cream cheese forms the creamy and tangy base of the cheese filling. Ensure it’s softened to room temperature for easy mixing and a smooth texture. Full-fat cream cheese provides the best richness and flavor.
4 ounces Gruyère cheese, grated: Gruyère is a classic choice for onion tarts. It’s a nutty, slightly salty cheese that melts beautifully and complements the caramelized onions perfectly. You can substitute with other cheeses like Swiss, Fontina, or even a sharp cheddar for a different flavor profile.
2 ounces Parmesan cheese, grated: Parmesan cheese adds a salty, umami-rich depth to the filling. Use freshly grated Parmesan for the best flavor and texture.
1 large egg: The egg acts as a binder, holding the cheese filling together and giving it a slightly richer texture.
1/4 cup heavy cream or crème fraîche: Heavy cream or crème fraîche adds extra richness and creaminess to the cheese filling. Crème fraîche will provide a slightly tangier note. You can substitute with whole milk for a lighter option, but the texture will be less rich.
Pinch of nutmeg (optional): A very small pinch of nutmeg adds a warm, subtle spice note that enhances the flavors of the cheese and onions. Be careful not to overdo it, as nutmeg can be overpowering.
1 box (14.1 ounces) refrigerated pie crusts (or homemade pie crust): For convenience, refrigerated pie crusts work wonderfully for this recipe. They are readily available and provide a flaky, buttery base. You can also use puff pastry for a different texture or make your own homemade pie crust for a truly from-scratch experience. Using two crusts will provide enough for the top and bottom of the tarts or for multiple smaller tarts.
Fresh thyme sprigs: For a beautiful and aromatic garnish.
Balsamic glaze: For drizzling over the finished tarts, adding a touch of sweetness and tanginess.

Directions:

Creating these Caramelized Onion and Cheese Tarts is a rewarding process, broken down into manageable steps. While caramelizing onions takes time, the hands-on effort is minimal, and the results are well worth it. Follow these detailed instructions for perfect tarts every time:

Start by peeling and slicing the yellow onions thinly.
In a large skillet, heat the olive oil and butter over medium heat.
Once hot, add the sliced onions and sprinkle with a little salt. Stir to coat the onions in the oil and butter.
Cook the onions slowly, stirring occasionally, until they are soft and caramelized. This usually takes about 25-30 minutes.
Stir in the granulated sugar and cook for an additional 5 minutes. Add the balsamic vinegar, thyme, and adjust seasoning with salt and pepper. Remove from heat and let cool.
In a mixing bowl, combine the softened cream cheese, Gruyère cheese, Parmesan cheese, egg, heavy cream, nutmeg, and a pinch of salt and pepper. Mix until smooth.
Preheat your oven to 375°F (190°C).
Roll out the pie crust and fit it into a tart pan. Pour the cheese mixture into the crust, then top with the caramelized onions.
Bake in the preheated oven for 25-30 minutes or until the tart is golden brown and set.
Let cool slightly before serving. Drizzle with balsamic glaze and garnish with fresh thyme sprigs.

how to serve Caramelized Onion and Cheese Tarts

These tarts are best served warm or at room temperature. Slice them into wedges for easy serving. They pair well with a simple green salad for a complete meal or can be enjoyed as a delightful appetizer. Drizzle with balsamic glaze just before serving for an added touch!

how to store Caramelized Onion and Cheese Tarts

To store leftovers, let the tarts cool completely, then cover them with plastic wrap or aluminum foil. They can be kept in the refrigerator for up to 3 days. To reheat, place them back in the oven at 350°F (175°C) until heated through.

tips to make Caramelized Onion and Cheese Tarts

Be patient when caramelizing the onions; it’s key to develop their sweetness.
Use fresh herbs when possible for the best flavor.
If you have time, consider making your homemade pie crust for an extra special touch.

variation

Feel free to experiment with different cheeses, such as feta or goat cheese, for a different flavor. You can also add cooked bacon or sautéed mushrooms to the filling for added richness.

FAQs

Q: Can I make the tarts ahead of time?
A: Yes! You can prepare the filling a day ahead and assemble the tart just before baking.

Q: Can I freeze these tarts?
A: Yes, you can freeze the tarts before baking. Wrap them tightly and store in the freezer for up to 2 months. Bake from frozen, adding a few extra minutes to the baking time.

Q: What can I serve with these tarts?
A: These tarts pair wonderfully with a fresh salad, roasted vegetables, or a glass of wine. Enjoy!