Southern Pan Fried Chicken and Gravy

Wash the chicken in cold water and drain it well. Place the chicken in a stainless-steel or glass baking dish. Pour the milk-yogurt mixture or the buttermilk over the chicken, making sure all the pieces are coated. Set aside for 1 hour. Meanwhile preheat the over to 200 degrees. Set a wire rack on a baking sheet and place it in the oven. Place the chicken pieces in a colander to drain. Put the oil in a deep heavy skillet or saute pan, place it over medium-high heat and heat it to 350 degrees. Combine the salt,m black pepper, cayenne and flour in a heavy paper bag. Shake well to mix. As the oil approaches 250 degrees, remove the pieces of chicken from the colander 1 at a time, shaking off any excess liquid, and add them to the bag, shaking well to coat. Reserve the leftover flour. When the fat reaches 350 degrees, place the chicken pieces in the pan 1 at a time, skin-side down. Start with the dark meat pieces, which take a little longer. Cool in batches, if necessary; you do not want to crowd the chicken, and the oil should come up around the edges of each piece. Cover the pan, reduce the heat a little (you want to keep the temperature at 350 degrees) and fry 5-7 minutes until the underside is brown. Turn the chicken, cover the pan again and dry for another 5-7 minutes. Remove the cover and continue cooking until the chicken is perfectly crisp and cooked all the way though, about 15 minutes more. Transfer the chicken to the wire rack to drain and keep warm while you fry the rest and make the gravy. Carefully pour all but 2-3 tablespoons of the fat out of the skillet, leaving all the little browned bits in the pan. Place the pan back on the stove over the medium heat. Add 2 tablespoons of the reserved flour to the fat, whisking it in and stirring constantly until it begins to brown. Slowly add the 2 cups milk and the onion and continue cooking, stirring often, until the desired consistency if reached, about 5 minutes. Taste the gravy, add salt and pepper to taste and pour into a gravy boat to serve.