Go Back
Caramelized Onion & Gruyère Cheese Puff Pastry Tart

Caramelized Onion & Gruyère Cheese Puff Pastry Tart Appetizer

Want a tart so rich and savory it tastes like it came from a French bakery? This Caramelized Onion & Gruyère Cheese Puff Pastry Tart delivers deeply caramelized onions and a creamy, cheesy custard filling wrapped in genuinely flaky puff pastry.
Print Recipe Pin Recipe
Prep Time 30 minutes
Cook Time 30 minutes
Total Time 1 hour
Servings: 8
Course: Appetizer, Appetizer recipe, Gluten-free
Cuisine: American
Calories: 320
Ingredients Equipment Method Notes

Ingredients
  

  • This recipe comes together in three parts: the puff pastry base deeply caramelized onions, and a silky tofu-based custard filling.
  • For the Tart
  • 1 sheet puff pastry thawed (about 12 oz, check the label for vegan-friendly ingredients)
  • 3 large onions sliced
  • 2 oz vegan butter
  • 3 sprigs fresh thyme
  • For the Custard Filling
  • 14 oz silken tofu drained
  • 3/4 cup unsweetened plant-based cream oat or soy cream work well
  • 2 tablespoons cornstarch
  • 1 tablespoon nutritional yeast
  • 1/4 teaspoon ground turmeric for color
  • 3.5 oz vegan gruyère-style cheese grated
  • 1/4 cup vegan parmesan grated
  • Salt and pepper to taste
  • Silken tofu genuinely makes this custard work. Its smooth creamy texture blends into something that sets up firm in the oven, closely mimicking the texture of an egg-based filling.

Equipment

  • This recipe uses a few specific tools to get that classic tart shape and texture. Here's what to have ready:
  • 9-inch tart tin
  • Baking beans or pie weights (for blind baking)
  • Parchment paper
  • Large frying pan (for caramelizing the onions)
  • Blender or food processor (for the tofu custard)
  • Mixing bowl
  • No stand mixer required. A tart tin, a frying pan, and a blender handle the entire process.

Method
 

  1. Step 1- Preheat and Prep the Pastry
  2. Heat your oven to 190°C (375°F). Line a 9-inch tart tin with the puff pastry sheet.
  3. Step 2- Blind Bake the Crust
  4. Fill the tart with baking beans or pie weights and blind bake for 15 minutes. Remove the beans and parchment, then bake for another 10 minutes until lightly golden.
  5. Step 3- Caramelize the Onions
  6. While the pastry bakes, melt the vegan butter in a frying pan over medium heat and add the sliced onions. Turn the heat to low and cook for 20 to 25 minutes, until the onions turn deeply caramelized, stirring occasionally for even color.
  7. Step 4- Make the Tofu Custard
  8. In a blender, combine the silken tofu, plant-based cream, cornstarch, nutritional yeast, and turmeric. Blend until completely smooth. Transfer to a bowl and stir in the grated gruyère-style cheese and chopped thyme. Season with salt and pepper.
  9. Step 5- Combine and Fill
  10. Stir the caramelized onions into the tofu custard mixture, then pour everything into the pre-baked tart shell.
  11. Step 6- Top and Bake
  12. Sprinkle the vegan parmesan over the top and bake for 25 minutes, or until the filling sets and turns golden brown.
  13. Step 7- Cool and Serve
  14. Let the tart cool for 5 minutes before slicing.

Notes

Nutrition Breakdown (Per Serving)

Here's an estimated nutrition breakdown per serving, based on 8 total servings from this recipe:
  • Calories- approximately 320 kcal
  • Carbohydrates- 24g
  • Protein- 10g
  • Fat- 20g
  • Saturated Fat- 7g
  • Sodium- 320mg
  • Fiber- 2g
  • Sugar- 6g