Tarte au Comté with Caramelized Onions

1.Preheat your oven to 200°C (390°F).

2.Roll out the puff pastry on a lightly floured surface and fit it into a tart pan. Trim any excess pastry from the edges.

3.Prick the base of the pastry with a fork to prevent it from puffing up. Place it in the refrigerator to chill while you prepare the filling.

4.In a large skillet, melt the butter with the olive oil over medium heat. Add the sliced onions and cook, stirring occasionally, until they become soft and translucent, about 10 minutes.

5.Sprinkle the sugar over the onions, increase the heat to medium-high, and continue cooking until the onions are golden brown and caramelized, about another 10-15 minutes. Remove from heat and let cool slightly.

6.In a mixing bowl, whisk together the eggs and heavy cream until well combined. Season with salt and black pepper to taste.

7.Stir in the grated Comté cheese and fresh thyme leaves into the egg and cream mixture.

8.Spread the caramelized onions evenly over the chilled pastry base.

9.Pour the egg, cream, and cheese mixture over the onions, ensuring it is evenly distributed.

10.Place the tart in the preheated oven and bake for 25-30 minutes, or until the filling is set and the top is golden brown.

11.Remove from the oven and let cool slightly before serving. Cut into slices and enjoy warm or at room temperature.