Caramelized Onion Tart

1. Cook Onions

Heat 4 tablespoons of olive oil or butter in a low-sided, heavy-bottomed pan over medium heat. Once the oil or butter is hot, add 6 medium onions that have been thinly sliced, along with 3 sprigs of thyme and a pinch of salt. Cook the onions gently for 20 to 30 minutes, stirring occasionally, until they turn golden and become soft. Remove the thyme sprigs and let the onions cool.

2. Prepare Dough

Roll out 10 ounces of Tart and Pie Dough on a lightly floured surface to your desired thickness. Transfer the dough onto a parchment-lined baking sheet and chill in the refrigerator for about 10 minutes.

3. Assemble Tart

Spread the cooled, caramelized onions evenly over the center of the chilled dough, leaving a border around the edges. Gently fold the edges of the dough over the onions, pleating as necessary to create a rustic edge.

4. Apply Egg Wash

Beat together 1 egg with 1 tablespoon of milk or water to create an egg wash. Brush this mixture over the dough edges with a pastry brush.

5. Bake Tart

Preheat your oven to 375°F. Place the tart on the bottom rack of the oven and bake for 45 to 50 minutes, or until the crust is golden brown and fully cooked. Once baked, transfer the tart to a cooling rack and let it cool before slicing.