Skillet Chicken Pot Pie with Butternut Squash

INGREDIENTS

• 1/4 olive oil
• 1 frozen white pearl onions, thawed
• 4 garlic cloves, finely chopped
• 1 chopped fresh sage
• 1 small bunch kale, center ribs and stems removed, leaves chopped
• Kosher salt, freshly ground pepper
• 1/4 all-purpose flour
• 3 low-sodium chicken broth
• 1/2 small butternut squash, peeled, cut into 1/2-inch pieces (about 1 1/2 cups)
• 1/2 rotisserie chicken, meat torn into bite-size pieces (about 1 1/2 cups)
• 1 sheet frozen puff pastry (such as Dufour or Pepperidge Farm), thawed
• 1 large egg