Slow Cooker Chicken Pot Pie

1. in a 5–6-quart slow cooker, whisk together the wine, flour, 1/2 cup water, and 1/2 tsp. each of salt and pepper. 2. Add the carrots, celery, onion, and chicken and toss to combine. Cook, covered, until the chicken is cooked through and easily pulls apart, 6-7 hours on low or 4-5 hours on high. 3. When the chicken has 30 minutes left to cook, heat oven to 400 degrees. Cut the puff pastry into 8 rectangles and place on a parchment-lined baking sheet. Brush with the egg and bake until puffed and golden brown, 20-25 minutes. 4. Gently fold the peas and dill into the chicken and vegetables and cook, covered, until heated through, about 3 minutes. 5. Spoon into bowls, sprinkle with additional dill if desired, and top with the puff pastry.