Fried Chicken - ultra craggy crispy crust!

Ingredients

For 10 servings

• 1.8 kg/ 3.6lb bone in, skin on small thighs (< 200g/7oz), drumsticks, whole wings, breast (< 200g/7oz) ((Note 1))
• 1 cup buttermilk ((Note 2 for sub))
• 1 tbsp salt
• 1 egg
• 2 1/4 cups flour (, plain / all purpose)
• 3/4 cup corn flour / cornstarch
• 3 tsp salt
• 3/4 tsp celery salt
• 1.5 tbsp black pepper ((Note 2))
• 1.5 tsp sweet paprika ((ie. not hot or smoked))
• 1/2 tsp cayenne pepper (, optional)
• 1.5 tsp onion powder
• 3 tsp garlic powder
• 1 tsp mustard powder
• 3/4 tsp ginger powder
• 1.5 tsp dried thyme
• 1.5 tsp dried oregano
• 1.5 - 2 litres / quarts vegetable oil ((or canola or peanut, Note 8 for re-use))