Between pieces of plastic wrap or waxed paper, place each chicken breast smooth side down; gently pound with flat side of meat mallet or rolling pin until about 1/2 inch thick. In small shallow dish, mix flour with 1 teaspoon salt and 1/2 teaspoon pepper; dip each chicken breast into flour mixture, coating all sides.
In 10-inch skillet, heat 2 tablespoons vegetable oil over medium-high heat. Cook chicken breasts in oil 6 to 8 minutes, turning once, or until brown. In small bowl, mix cooking sauce and lemon juice.
Pour sauce mixture over chicken. Reduce heat to medium-low; simmer 5 to 10 minutes or until juice of chicken is clear when center of thickest part is cut (at least 165 degrees F).
