Caramelized Onion Tart with Olives

Delight your taste buds with this savory and elegant Caramelized Onion Tart with Olives—a perfect appetizer or light meal that beautifully balances sweet and salty flavors. Layers of golden, flaky puff pastry form the base for a rich topping of slow-cooked caramelized onions, enhanced with fresh thyme and a splash of balsamic vinegar for depth. Kalamata olives add a briny pop of flavor, making each bite irresistible. With just 20 minutes of prep time and simple ingredients like buttery pastry and pantry staples, this tart is surprisingly easy to make yet impressive enough for entertaining. Serve it warm or at room temperature as a centerpiece for brunch, a side dish, or a party snack that guests will rave about.

Nutriscore Rating: 55/100

Prep Time:20 mins

Cook Time:50 mins

Total Time:70 mins

Servings: 6

Ingredients

• 1 sheet Puff pastry sheet
• 3 medium Yellow onions
• 2 tablespoons Olive oil
• 1 tablespoon Unsalted butter
• 1 teaspoon Fresh thyme leaves
• 2 teaspoons Balsamic vinegar
• 0.5 teaspoon Salt
• 0.25 teaspoon Black pepper
• 0.5 cup Pitted Kalamata olives
• 1 large Egg
• 1 tablespoon Water
• 1 tablespoon All-purpose flour (for dusting)

Directions

Step 1

Preheat your oven to 400°F (200°C).

Step 2

On a clean surface, lightly dust with flour and roll out the puff pastry sheet to a rectangle about 12x10 inches. Transfer it to a baking sheet lined with parchment paper.

Step 3

Using a knife, lightly score a 1-inch border around the edges of the puff pastry, being careful not to cut all the way through. This will create a raised crust when baked. Prick the center area with a fork a few times to prevent it from puffing up too much.

Step 4

Place the puff pastry in the refrigerator to chill while you prepare the topping.

Step 5

Slice the onions thinly into half-moon shapes.

Step 6

Heat a large skillet over medium heat. Add the olive oil and butter, allowing the butter to melt.

Step 7

Stir in the sliced onions, fresh thyme leaves, salt, and black pepper. Cook for about 25-30 minutes, stirring occasionally, until the onions are deeply golden and caramelized.

Step 8

Add the balsamic vinegar to the onions and stir well to deglaze the pan. Cook for another 2 minutes, then remove from heat and let cool slightly.

Step 9

In a small bowl, whisk together the egg and water to create an egg wash.

Step 10

Remove the puff pastry from the refrigerator. Brush the edges (the border) with the egg wash.

Step 11

Spread the caramelized onions evenly over the center of the pastry, staying within the scored border.

Step 12

Scatter the pitted Kalamata olives over the top of the onions.

Step 13

Bake in the preheated oven for 20-25 minutes, or until the pastry is golden and puffed.

Step 14

Remove from the oven and let it cool slightly before slicing into squares or rectangles. Serve warm or at room temperature.

Nutrition Facts

Serving size	(858.0g)

Amount per serving	% Daily Value*
Calories	2374.2

Total Fat 174.3g	0%
Saturated Fat 43.0g	0%
Polyunsaturated Fat 4.6g
Cholesterol 250.5mg	0%
Sodium 4407.1mg	0%
Total Carbohydrate 173.0g	0%
Dietary Fiber 15.8g	0%
Total Sugars 20.2g
Protein 31.8g	0%

Vitamin D 53.8IU	0%
Calcium 218.2mg	0%
Iron 11.8mg	0%
Potassium 943.3mg	0%

*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

Source of Calories

Fat: 65.7%

Protein: 5.3%

Carbs: 29.0%