Caramelized Onion and Cheese Tarts Recipe
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.
- 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
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
- 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.
- 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.
- 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.
- 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
