Creamy Chicken Potpie Soup

Name: Creamy Chicken Potpie Soup
Ingredients: 1 sheet frozen puff pastry (from 1 [17.3-ounce] package), thawed; 1 large egg; 1/2 cup, plus 1 tablespoon, heavy whipping cream, divided; Flaky sea salt, to taste; 3 tablespoon unsalted butter; 1 yellow onion, chopped (about 1 1/2 cups); 1 cup thinly sliced carrots; 1 cup thinly sliced celery; 2 teaspoons finely chopped garlic; 1 teaspoon chopped fresh thyme, plus more for garnish; 1/4 cup all-purpose flour; 1/3 cup dry white wine; 4 cups chicken broth; 1 1/2 cups (1/2-inch) diced peeled Yukon Gold potato; 1 1/4 teaspoon kosher salt; 1/2 teaspoon black pepper, plus more for garnish; 2 cups packed shredded rotisserie chicken (about 12 ounces); 1/2 cup frozen green peas