Cheesy Caramelized Onion Tart Recipe
Prep Time:
15 minutes
Cook Time:
1 hour
Servings:
6 servings
Ingredients
  • 1 tablespoon butter
  • 1 tablespoon olive oil
  • 2 large Vidalia onions, thinly sliced
  • ½ teaspoon salt
  • ¼ teaspoon ground black pepper
  • 1 sheet thawed puff pastry
  • 1 cup shredded Swiss cheese
  • 2 tablespoons grated Parmesan cheese
  • 1 tablespoon finely chopped fresh chives
Directions
  1. Place butter and olive oil in a large pan with deep sides over medium heat.
  2. Once butter is melted and bubbly, add onions and cook, stirring occasionally, for 7-8 minutes until translucent. Add salt and pepper and stir.
  3. Lower heat to medium-low and cook for an additional 30 minutes, stirring occasionally to prevent sticking, until onions are soft and browned. If all the liquid evaporates, add water 1 tablespoon at a time to prevent the onions from burning. Lower the heat a little if necessary.
  4. Taste and adjust for salt if necessary.
  5. Preheat oven to 400 F.
  6. Unroll puff pastry sheet and place onto a parchment-lined baking sheet.
  7. Fold in all 4 sides about ½ inch and press gently to form finished edges. Prick the bottom all over with a fork.
  8. Evenly distribute the Swiss cheese on the pastry sheet, followed by the Parmesan cheese.
  9. Arrange the onions in an even layer on top of the cheese.
  10. Sprinkle the chives on top of the onions.
  11. Place the baking sheet in the oven and bake for 20-23 minutes until the pastry crust is lightly browned and cooked on the inside and the cheese is melted and hot.
  12. Let cool for about 5 minutes before slicing and serving. The tart can also be served at room temperature if desired.