Combine buttermilk and chicken pieces in large bowl, coating each piece.
Stir together flour, salt, pepper, garlic powder and paprika on piece of waxed paper.
Working with one piece of chicken at a time, lift out of buttermilk and let drain over bowl; gently shake off any excess buttermilk; roll chicken piece in flour mixture to evenly coat. Place on a large sheet of clean waxed paper.
Place 1-1/2 cups vegetable shortening in each of two 8-inch cast-iron or other heavy skillets. Heat over medium-high heat until shortening reaches about 360°F. If shortening begins to smoke, lower heat.
Carefully place chicken pieces in skillets; cover skillets. Cook, covered, about 22 minutes or until browned and crispy, turning chicken over several times. Transfer chicken to paper towels. Gently blot off excess fat.
Serve hot or warm, with prepared refrigerated mashed potatoes and peas, if desired.