Caramelized Onion and Cheese Tarts Recipe

Introduction

These Caramelized Onion and Cheese Tarts combine sweet, deeply caramelized onions with a rich, creamy cheese filling nestled in a flaky crust. Perfect for an elegant appetizer or a cozy snack, these tarts offer layers of flavor that will impress your guests.

Ingredients

• 3 large yellow onions (about 2 pounds)
• 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 (optional)
• Balsamic glaze for drizzling (optional)

Instructions

1. Step 1: Prepare the onions by peeling and slicing them thinly from root to stem. Heat olive oil and butter in a large skillet over medium heat. Add onions and reduce heat to low-medium low. Cook slowly, stirring occasionally for 30-45 minutes until golden brown.
2. Step 2: About 30 minutes into cooking, stir in sugar, balsamic vinegar, and thyme. Continue cooking 10-15 minutes until onions are deep brown and jam-like. Season with salt and pepper and set aside to cool.
3. Step 3: In a bowl, beat softened cream cheese, Gruyère, Parmesan, egg, and cream until smooth. Add a pinch of nutmeg if using. Taste and adjust salt and pepper if needed.
4. Step 4: Preheat oven to 375°F (190°C). Line a baking sheet with parchment paper. Unroll pie crusts and cut into desired tart shapes or use whole crust for a large tart. Place crusts on the baking sheet.
5. Step 5: Spread a layer of caramelized onions over each crust, leaving a small border. Top evenly with cheese filling. Avoid overfilling to prevent spillover.
6. Step 6: Bake for 20-25 minutes until crusts are golden and cheese filling is set with a light golden top. Cool slightly before garnishing with thyme sprigs and drizzling balsamic glaze if desired.
7. Step 7: Serve warm or at room temperature as an appetizer, snack, or light meal.

Tips & Variations

• Use a combination of butter and olive oil to enhance flavor and prevent burning when caramelizing onions.
• Substitute Gruyère with Swiss, Fontina, or sharp cheddar for different cheese profiles.
• For a tangier cheese filling, use crème fraîche instead of heavy cream.
• Make individual tartlets using a cookie cutter for a beautiful presentation.
• Add fresh herbs like rosemary or sage along with thyme to vary the herbaceous notes.

Storage

Store leftover tarts in an airtight container in the refrigerator for up to 3 days. Reheat gently in a preheated 350°F (175°C) oven for 10 minutes to crisp the crust and warm the filling. Avoid microwaving as it can make the crust soggy.

How to Serve

Serve this delicious recipe with your favorite sides.

FAQs

Can I make the caramelized onions ahead of time?

Yes, caramelized onions can be made up to 3 days in advance and stored in the refrigerator. This helps save time when assembling the tarts.

Can I use puff pastry instead of pie crust?

Absolutely. Puff pastry will give a lighter, flakier texture and adds a different dimension to the tarts. Adjust baking time as needed, usually slightly shorter.

Caramelized Onion and Cheese Tarts Recipe

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These Caramelized Onion and Cheese Tarts feature a rich, flaky pie crust filled with sweet, deeply caramelized onions and a creamy, savory cheese filling made from cream cheese, Gruyère, and Parmesan. Slow-cooked onions bring a jam-like sweetness balanced with thyme and balsamic vinegar, while the luscious cheese mixture adds depth and richness. Perfect as an elegant appetizer or light meal, these tarts combine simple ingredients into an irresistible treat.

• Author: nova
• Prep Time: 20 minutes
• Cook Time: 50 minutes
• Total Time: 1 hour 10 minutes
• Yield: 6–8 individual tarts or 1 large tart (serves 6-8) 1x
• Category: Appetizer
• Method: Baking
• Cuisine: French

Ingredients

Scale 1x2x3x

For the Caramelized Onions:

• 3 large yellow onions (about 2 pounds), peeled and thinly sliced
• 2 tablespoons extra virgin 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

For the Cheese Filling:

• 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)
• Salt and freshly ground black pepper, to taste

For the Tart Crust:

• 1 box (14.1 ounces) refrigerated pie crusts or homemade pie crust

Optional Garnishes:

• Fresh thyme sprigs
• Balsamic glaze

Instructions

1. Caramelize the Onions: Peel and thinly slice the yellow onions. In a large heavy-bottomed skillet, heat olive oil and butter over medium heat until melted and shimmering. Add onions and stir to coat in fat. Reduce heat to low-medium low and cook onions slowly, stirring occasionally, for 30–45 minutes until they become deeply golden and jam-like in consistency. After 30 minutes, add sugar, balsamic vinegar, and thyme; stir well. Continue cooking for 10–15 minutes more until rich brown. Season with salt and pepper and remove from heat to cool.
2. Prepare the Cheese Filling: In a medium bowl, combine softened cream cheese, grated Gruyère, Parmesan, egg, and heavy cream or crème fraîche. Beat with a whisk or mixer until smooth and uniform. Add a pinch of nutmeg if using, and season with salt and pepper to taste. Mix thoroughly.
3. Assemble and Bake the Tarts: Preheat oven to 375°F (190°C). Line a baking sheet with parchment paper. Remove pie crusts from fridge and let soften slightly. Unroll and cut into desired tart shapes or use whole crust for a large tart. Place crusts onto the baking sheet. Evenly spread caramelized onions over each crust, leaving a small border, then top evenly with the cheese filling, avoiding overfilling. Bake for 20–25 minutes until crusts are golden and filling is set with lightly golden tops. Remove from oven and cool slightly.
4. Serve and Garnish: Garnish tarts with fresh thyme sprigs and a drizzle of balsamic glaze if desired. Serve warm or at room temperature as an appetizer, snack, or light meal.

Notes

• Use low heat and patience when caramelizing onions for best results — rushing can cause burning.
• You can substitute Gruyère with Swiss, Fontina, or sharp cheddar for varied flavor.
• Crème fraîche adds tang but heavy cream can be used for a milder taste.
• Refrigerated pie crusts offer convenience, but puff pastry or homemade crusts work well too.
• Adjust salt carefully, as cheeses and caramelized onions already contain salt.
• Nutmeg is optional but adds a warm spice note; use sparingly.
• Leftover tarts can be refrigerated and gently reheated before serving.

Keywords: caramelized onion tart, cheese tart, savory tart, onion and cheese, Gruyère tart, French appetizer, easy tart recipe, homemade tart