Cut each breast into three equal pieces. Place on a firm cutting board, cover with plastic wrap, and gently pound flat with a mallet or rolling pin. Whisk the egg in a bowl with 2 T of water. Combine the Bridgeport Seasoning, chopped walnuts and flour in a large dish. Dip the individual pieces of chicken in the egg and then the walnut mixture. Shake off excess coating and set aside. Heat a large sauté pan over medium high heat. Add the oil. When hot, add the pieces of chicken and brown each side (about 3-5 minutes per side).