In a bowl, put the chicken pieces and toss with 3 cups buttermilk, 2 tablespoons of salt, and 1 tbsp black pepper. Cover and marinate for a minimum of 2 hour or keep it in the refrigerator for up to one day.
Set a rack on a tray or baking sheet to place cooked chicken and drain.
In a big bowl or, preferably, a large sealable plastic bag, mix the 1 1/2 cups of flour, 1 teaspoon of salt and 2 teaspoons of pepper. Optional: You can add 1 tsp hot pepper or paprika
Pour oil into a wide heavy-bottomed cast-iron skillet with high sides and a lid, fill it only half way of the skillet Heat the oil slowly to 350 degrees (Use a thermometer) over medium-high heat.
Remove the chicken from the brine and drain any excess brine liquid. Put the chicken pieces in to the plastic bag filled with flour mixture and shake it well to coat or toss them with the flour mixture in the bowl to coat chicken pieces.
Shake off the excess flour and add chicken pieces skin-side down into hot oil. Do not overcrowd the pan, fry the pieces in batches. When you add the chicken pieces the oil temperature goes down. Adjust the temperature to keep it at 350 degrees. Cover the pan with a lid for five to ten minutes. Remove the lid and turn over the chicken pieces. Cook for another 5-10 minutes uncovered (Do not cover with lid) until they are cooked well and turn in to deep golden brown color. Turn the chicken often to prevent burning and get cooked evenly. The color indicates whether it is cooked so watch out for the color and remove it from the oil without burning the crust.
Once the chicken pieces are golden brown then remove it from the oil to a rack, to drain all excell oil.
Serve warm with Pickle Garlic Relish, hot sauce etc.