In a long deep dish or resealable bag add the buttermilk, coriander, garlic, salt, thyme and cayenne. Mix well. Add the chicken into the marinade and marinate for 8 hours or up to 24 hours.
1 hour before frying, remove the chicken from the marinade and pat dry.
20 minutes before frying, add the flour, cayenne and salt to a large brown bag. Place the chicken into the bag and shake well to coat.
Remove the chicken from the bag and lay on a cooling rack for 10 minutes.
Meanwhile, pour the oil into a large cast iron skillet. Use enough oil to submerge the chicken pieces halfway. Heat the oil to 350-400 degrees.
In two batches, fry the chicken—for a total of 16 to 18 minutes, until the internal temperature reaches 165°, turning and rotating chicken every 4 minutes.
Remove the chicken to a clean cooling rack.
Brush the desired amount of chili paste to each side of the chicken and then lightly sprinkle with salt. Serve warm with a pickle.