Coat chicken in 1/2 cup buttermilk. Dredge cornmeal mixed with 1/4 = cup flour, salt, and pepper. Heat 2 tablespoons oil over medium-high = heat. Add half of chicken and cook, turning once, until cooked = throughout, about 6 minutes total. Repeat with remaining chicken. Remove = chicken from pan. Add remaining 2 teaspoons flour and cook, stirring, 1 = minute. Whisk broth and 1/2 cup remaining buttermilk into pan drippings. = Simmer, stirring, 2 minutes. Season with salt and pepper. Serve gravy = ladled over chicken.