Caramelized Onion and Goat Cheese Tart

Instructions

1. Caramelize the onions
   Heat the butter and olive oil in a large skillet over medium-low heat. Add the sliced onions and a pinch of salt. Cook slowly, stirring occasionally, for about 45 minutes until the onions are deeply golden and caramelized. Add the thyme, balsamic vinegar, and brown sugar in the last 5 minutes of cooking. Set aside to cool slightly.
2. Prepare the pastry
   Preheat oven to 375°F (190°C). Roll out the puff pastry on a lightly floured surface to fit a 9-inch (23cm) tart pan with a removable bottom. Press the pastry into the pan, trim the edges, and prick the bottom with a fork. Refrigerate for 15 minutes.
3. Blind bake the crust
   Line the chilled pastry with parchment paper and fill with baking weights or dried beans. Bake for 15 minutes, then remove the weights and parchment. Brush the crust with beaten egg and bake for another 5 minutes until lightly golden. Reduce oven temperature to 350°F (175°C).
4. Prepare the filling
   In a medium bowl, whisk together the eggs and heavy cream. Season with salt and pepper. Crumble half of the goat cheese into the mixture and stir gently.
5. Assemble the tart
   Spread the caramelized onions evenly over the par-baked crust. Pour the egg and cream mixture over the onions. Crumble the remaining goat cheese on top and sprinkle with additional thyme leaves.
6. Bake the tart
   Bake the tart for 25-30 minutes until the filling is set and the top is golden brown. The center should be just slightly jiggly but not liquid.
7. Rest and serve
   Allow the tart to cool for at least 15 minutes before removing from the pan. This helps the filling to set completely. Serve warm or at room temperature with a light green salad.