- 1 package frozen puff pastry (available in Freezer Section), thawed in refrigerator
- 1 tablespoons extra-virgin olive oil
- 1 tablespoon butter
- 3 large Vidalia onions or other sweet variety, thinly sliced
- 4 thyme sprigs, plus more for garnish
- Kosher salt and freshly cracked black pepper
- 1/3 cup good quality beef stock
- 1 cup shredded gruyere cheese
1. Preheat the oven to 400 degrees F. Line a baking sheet with parchment paper or spray with cooking spray.
2. Heat olive oil and butter in a large skillet over medium-low heat. Add onions and thyme sprigs and season well with salt and pepper, to taste. Cook, stirring occasionally, until the onions begin to brown. Add the stock, a tablespoon at a time, as the pan gets dry, scraping and stirring the brown bits that are stuck to the bottom oft the pan. When the onions are caramelized to a dark golden color, remove from the heat and discard the leafless thyme sprigs (the leaves fall off while cooking).
3. While onions are caramelizing (or afterwards) roll out two sheets of puff pastry to 1/8 inch thickness (or a 10″ x 16″ square). Using a glass or a round cookie cutter, cut out 3″ – 4″ circles in the dough. Discard the scraps. With a fork, pierce the center of each circle to prevent rising; do not pierce the edges. Bake until the outer edges have puffed and are very lightly golden in color (slightly UNDERCOOKED); about 5 to 7 minutes. Set aside.
4. When ready to serve, preheat the oven to 350 degrees F. Place a small heap of the caramelized onions in the center of each pastry shell, top with some grated gruyere and bake in the oven until the cheese is melted and the crust is golden brown, 5 to 7 minutes. Remove from oven. Serve immediately and enjoy!