Clean wings, by removing stray feathers. Rinse and pat dry with paper towels.
If not done already, split chicken wings in half by cutting through the joints.
Mix together black pepper, salt, garlic and paprika.
Place wings in a large resealable bag, then sprinkle combined salt and spices over wings.
Massage wings until evenly coated.
Remove as much air as you can then seal food bag and place in fridge overnight to marinate.
Once wings have marinated mix together flour and cornstarch.
Transfer wings to a clean large bowl and sprinkle half of flour mixture and toss vigorously until wings are coated.
Sprinkle the balance of the flour mixture and toss vigorously once more.
Line baking sheets with parchment paper, then arrange wing pieces on baking sheets. Make sure you use both baking sheets, do not crowd the wings.
Place wings in preheated oven at 475. One baking sheet on the middle rack in the oven, and the other on the bottom rack.
While wings are cooking place butter, Sriracha and mirin into a small saucepan and place on a high heat.
Whisk vigorously until butter melts and begins to bubble.
Lower heat, and continue to stir with a spoon until sauce begins to thicken just a little.
Once sauce has thickened lower heat to low to keep sauce warm.
Allow wings to cook for 15 mins then remove wings on bottom rack and swap wings that were on the middle rack and place them on the bottom rack.
Turn wings over, then return to the oven on the middle rack.
Allow wings to cook for another 15 mins, then remove wings on the bottom rack, turn them and return to the bottom rack.
Remove sauce from heat, whisk vigorously if needed.
Remove wings on the middle rack, and tip into a clean bowl.
Drizzle half a cup of the sauce over the wings and toss.
Return wings to baking sheet and place on middle tray to continue cooking for 5-10 mins until sauce has absorbed and wings become crispy.
Once wings on middle tray are done remove from oven and set aside.
Remove wings on bottom tray and place in a bowl, drizzle with 1/2 cup of sauce, toss and return to baking sheet.
Place newly coated wings on middle tray.
Allow that batch of wings to absorb the sauce and become crispy.
Place all of the wings on a large platter and drizzle with remaining sauce.
Serve immediately.