Butternut Squash Galette

Bahan-bahan (6 porsi)

• 2 large yellow onion (sliced 1/8th inch)
• 1/2 teaspoon Kosher salt (to taste)
• 2 tablespoons extra virgin olive oil (divided)
• 11 -inch refrigerated pie crust dough (store bought or homemade)
• 12 ounces peeled and sliced butternut squash (from a 20 oz squash (see below))
• Freshly ground black pepper (to taste)
• 1/2 cup grated Parmesan cheese
• 2 teaspoons fresh thyme leaves
• 1 large egg (beaten)