In a 5 to 6 qt. slow cookery, whisk together the wine, flour, 1/2 cup water and 1/2 each salt and pepper.

Add the carrots, celery, onion and chicken and toss to combine. Cook covered, until the chicken is cooked through and easily falls apart 6 to 7 hours on low or 4 to 5 hours on high.

When the chicken has 30 minutes left to cook, heat oven to 400°F. Cut the puff pastry into 8 rectangles and place on a parchment-lined baking sheet. Brush with egg and bake until golden brown, 20 to 25 minutes.

Gently fold the peas and dill into the chicken and vegetables and cook, covered, until heated through, about 3 minutes. Spoon into bowls and serve with additional if desired and top with the puff pastry.