Light Chicken Potpie

INGREDIENTS

• 4 tablespoons cold unsalted butter, cut into small pieces
• 5 medium carrots, cut into large chunks
• 1 cup all-purpose flour, plus more for dusting
• 1 large egg
• 1 to 2 teaspoons chopped fresh thyme
• 1/3 cup 2% milk
• 3 cups shredded rotisserie chicken, skin removed
• 3 tablespoons all-purpose flour
• 1/2 cup minced fresh parsley
• 1/4 teaspoon baking powder
• 1/2 cup fat-free plain Greek yogurt
• 1/4 teaspoon fine salt
• 3 stalks celery, sliced
• 2 tablespoons extra-virgin olive oil
• 1 cup frozen peas
• 1 large onion, finely diced
• 2 tablespoons 2% milk
• Kosher salt and freshly ground pepper
• 2 small russet potatoes
• 4 1/2 cups low-sodium chicken broth