Take a large food safe plastic zip seal bag and add all the dry ingredients for the chicken. Shake well.
Dredge the chicken in buttermilk then place in the bag. Repeat with the other chicken breast. Shake the bag well to coat the chicken.
Place the chicken onto a plate or tray lined with greaseproof paper and allow to rest for 30 minutes before frying.
Heat a deep fryer or wok with vegetable oil until very hot. Add the chicken and deep fry until cooked through. This will depend on the size and thickness of the chicken, but a medium sized breast will take around 10 minutes. Once thoroughly cooked through, remove from oil and drain on kitchen paper.
Meanwhile, make the creamed corn relish. Place the frozen sweetcorn into a microwave safe bowl, cover with water and microwave for 5 minutes. Drain, cool for 5 minutes, then add the mayonnaise and seasoning. Using a hand blender, roughly puree the relish. Set aside.
Toast the buns. Place chicken fillets on the bottom buns, then top with the corn relish and remaining ingredients.