Dessert

Golden Caramelized Onion & Trio-Cheese Savory Tarts Recipe

Bymia larkspur December 9, 2025December 9, 2025

Introduction

These Golden Caramelized Onion & Trio-Cheese Savory Tarts bring together sweet, slow-cooked onions and a rich blend of cheeses for a deliciously savory treat. Perfect as an appetizer or light meal, they’re easy to make and bursting with flavor.

A close-up view of several mini tarts arranged on a white marbled surface, each tart showing distinct layers starting with a golden-brown, flaky crust at the bottom, topped with a smooth and glossy light yellow custard filling. Sitting on the custard is a spiral of caramelized onion rings, soft and translucent with a rich golden-brown color, finished with a fresh green herb sprig in the center of each tart. The tarts have a warm, inviting look with a mix of smooth and textured layers. photo taken with an iphone --ar 4:5 --v 7

Ingredients

3 large yellow onions, thinly sliced
2 tbsp olive oil
1 tbsp unsalted butter
1 tsp granulated sugar
½ tsp balsamic vinegar
½ tsp dried thyme (or 1 tsp fresh)
Salt and freshly ground black pepper
8 oz cream cheese, softened
4 oz Gruyère cheese, grated
2 oz Parmesan cheese, grated
1 large egg
¼ cup heavy cream or crème fraîche
Pinch of nutmeg (optional)
1 box (14.1 oz) refrigerated pie crusts (or homemade crust)
Optional garnish: fresh thyme sprigs, balsamic glaze

Instructions

Step 1: Warm olive oil and butter in a heavy skillet over medium heat. Add the sliced onions and cook gently for 30–45 minutes, stirring occasionally, until they turn a deep golden color.
Step 2: During the last 10–15 minutes of cooking, stir in sugar, thyme, and balsamic vinegar. Season with salt and pepper to taste, then remove from heat and let cool.
Step 3: In a bowl, combine softened cream cheese, grated Gruyère, grated Parmesan, egg, and heavy cream. Beat until smooth. Add nutmeg if using and adjust salt and pepper as needed.
Step 4: Preheat the oven to 375°F (190°C) and line a baking sheet with parchment paper. Unroll the pie crusts and cut into desired shapes or keep whole for a large tart. Place crusts on the baking sheet.
Step 5: Spoon the caramelized onions evenly over the crusts, then spread the cheese filling on top, leaving a small border around edges.
Step 6: Bake for 20–25 minutes until the crust is golden and the cheese filling is lightly browned on top.
Step 7: Let the tarts cool for a few minutes before serving. Garnish with fresh thyme sprigs and a drizzle of balsamic glaze if desired.

Tips & Variations

Use fresh thyme instead of dried for a brighter herb flavor.
Add a sprinkle of chopped walnuts or pecans for extra texture.
Try swapping Gruyère for sharp cheddar or fontina for a different cheese profile.
For a vegetarian version, ensure your pie crust contains no animal fats.

Storage

Store leftover tarts in an airtight container in the refrigerator for up to 3 days. Reheat gently in a 350°F (175°C) oven for 5–10 minutes to preserve crispness. Avoid microwaving to keep the crust flaky.

How to Serve

The image shows several small round tarts placed on a white marbled surface. Each tart has a golden-brown flaky crust as the bottom layer, topped with a smooth, creamy yellow filling. On top of the filling, there is a swirl of soft, caramelized onions that are light brown with glossy texture. A small sprig of fresh green herb is placed in the center of each tart, adding a touch of color contrast. The tarts look shiny and well-baked, with a crispy crust edge that holds the filling neatly. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use homemade pie crust for this recipe?

Yes, homemade pie crust works wonderfully and adds a personal touch. Just roll it out to a similar thickness as store-bought crusts for even baking.

How do I know when the onions are properly caramelized?

The onions should be soft, deeply golden to light brown, and taste sweet with no raw onion bite. This usually takes 30–45 minutes of slow cooking with occasional stirring.