1Prepare the chicken marinade by combining buttermilk, sriracha sauce (optional), smoked paprika, onion powder, and garlic powder in a bowl. Mix well.
2Add the chicken thighs to the marinade, massage them, and let marinate in the fridge for at least 30 minutes.
3Prepare the seasoned flour mix by combining plain flour, cornflour, smoked paprika, onion powder, garlic powder, and celery salt in a bowl. Mix well.
4Make the mayonnaise by blending olive oil, a whole egg, white vinegar, and Dijon mustard using an immersion blender until smooth and thick.
5Prepare the tangy mayonnaise by combining plain mayonnaise, smoked paprika, garlic powder, tomato ketchup, horseradish, and Worcestershire sauce in a bowl. Mix well and season with sea salt flakes.
6Dredge the marinated chicken thighs in the seasoned flour, ensuring complete coverage and shake off any excess.
7Heat vegetable or canola oil in a large pot to 170°C/340°F.
8Fry the chicken thighs in batches for 7 minutes, flipping halfway through, until golden brown and crispy.
9Toast the burger buns in a preheated oven at 180°C/350°F on the grill setting for 1 minute on each side.
10Assemble the burgers: spread tangy mayonnaise on the bottom buns, add lettuce, tomato slices (season with sea salt flakes and black pepper), crispy chicken thighs, and pickles (optional).
11Top with the other bun halves, gently pressing down. Serve immediately.