Caramelized Onion Gruyere Tart
Enjoy this caramelized onion gruyere tart for brunch or serve it as an appetizer at your next get-together! It's sweet, savory, and delicious!
Servings: 9
Calories: 305kcal
Ingredients
- 1 sheet puff pastry
- 3 large onions thinly sliced
- 1 ½ cups gruyere cheese shredded
- 4 tablespoons butter
- salt to taste
- 1 egg
- 1 tablespoon water
Instructions
- Add the butter to a large pot and allow it to melt completely.
- Stir in the onions and cook for about 1 hour over medium-low heat. Make sure to stir occasionally. In the middle of the cooking process, add a splash of water to deglaze the bottom of the pot.
- Once the onions are nice and caramelized, turn off the heat and season them with salt, but not too much because the gruyere cheese is very salty.
- Line a baking sheet with parchment paper and pre-heat your oven to 375 degrees F.
- Place the thawed puff pastry on the baking sheet and pierce it several times with a fork.
- Add the cheese and then the caramelized onions all over the tart, leaving a ½ inch border. Whisk the egg and water, brush the border with the egg wash, and then bake for 20 minutes.
- Allow the tart to cool for 5-10 minutes, slice it into squares, and enjoy!
Notes
- Slice the onions thinly and evenly to ensure they cook and caramelize evenly.
- Caramelizing onions takes time, so be patient. Cook them over low to medium-low heat to gently coax out their natural sugars without burning them. Stir occasionally to prevent sticking and ensure even caramelization.
- Season the onions with salt once they're done cooking.
- Thaw the frozen puff pastry for 15-20 minutes before baking.
Nutrition
Calories: 305kcal | Carbohydrates: 17g | Protein: 9g | Fat: 23g | Saturated Fat: 10g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 9g | Trans Fat: 0.2g | Cholesterol: 38mg | Sodium: 267mg | Potassium: 109mg | Fiber: 1g | Sugar: 2g | Vitamin A: 365IU | Vitamin C: 4mg | Calcium: 238mg | Iron: 1mg