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

Wrap the dough in plastic wrap and refrigerate for 30 minutes.

Heat olive oil in a skillet over medium heat. Add sliced onions and cook, stirring occasionally, for about 20 minutes until golden brown.

Add balsamic vinegar and thyme, cooking for an additional 5 minutes. Remove from heat.

Preheat the oven to 375°F (190°C). Roll out the chilled dough and fit it into a pie dish.

In a bowl, whisk together eggs and cream. Stir in goat cheese, caramelized onions, and black pepper.

Pour the filling into the crust and bake for 30 minutes until set and golden.