In a mixing bowl, combine flour and salt. Add cold butter and mix until crumbly. Stir in ice water until dough forms.

Shape the dough into a disk, wrap in plastic wrap, and refrigerate for 30 minutes.

Preheat the oven to 400°F (200°C). Toss diced butternut squash with olive oil, salt, and pepper. Spread on a baking sheet and roast for 25 minutes until tender.

In a skillet over medium heat, add sliced onions and a bit of olive oil. Cook, stirring occasionally, for about 15 minutes until golden brown.

Roll out the chilled dough and fit it into a pie dish. Pre-bake the crust for 10 minutes.

In a bowl, whisk together eggs, cream, thyme, salt, and pepper. Stir in roasted squash, caramelized onions, and goat cheese.

Pour the filling into the pre-baked crust and bake at 375°F (190°C) for 30 minutes until set.

Let the quiche cool for a few minutes before slicing. Serve warm or at room temperature.