For the Chicken (or use leftover chicken or a rotisserie chicken)
- 1 pound boneless chicken breasts
- 2 cups chicken stock, preferably low-sodium
- 1 bay leaf
- 3 cloves garlic, halved
- A few sprigs of fresh herbs, such as thyme, rosemary, and sage
For the Chicken Pot Pie
- 1 tablespoon olive oil
- 1 tablespoon unsalted butter
- 1 cup diced onion
- 1 cup diced celery
- 12 to 16 ounces potatoes, cut into 1/2-inch chunks
- 1 1/2 cups frozen peas and carrots
- 2/3 cup heavy cream
- 2 tablespoons cornstarch
- Kosher salt and freshly ground black pepper, to taste
- 1 sheet puff pastry (about 7 to 8 ounces)
- 1 large egg
- Fresh chopped parsley, chives, or thyme leaves, for garnish, optional