BRINE THE CHICKEN (4-24 HOURS AHEAD)
In a large bowl, whisk together buttermilk, pickle juice, hot sauce, cayenne, salt, pepper, garlic powder, and paprika until combined.

If chicken thighs are uneven in thickness, pound the thicker portions lightly to create uniform pieces for even cooking.

Place chicken in the buttermilk mixture, ensuring all pieces are submerged. Cover and refrigerate for at least 4 hours, or up to 24 hours.

MAKE THE ROASTED JALAPEÑO SLAW
Heat a dry cast iron skillet over high heat until smoking. Place whole jalapeños in the pan and char on all sides, turning with tongs, about 8-10 minutes total. The skins should be blistered and blackened in spots.

Transfer roasted jalapeños to a small bowl and cover tightly with plastic wrap. Let steam for 10 minutes. Remove stems, seeds for medium heat or leave some seeds for extra heat, and skins. Dice finely.

In a small bowl, whisk together mayonnaise, sour cream, lime juice, vinegar, honey, cumin, and salt. Stir in the diced roasted jalapeños.

In a large bowl, toss together green cabbage, purple cabbage, carrots, and green onions. Pour dressing over the vegetables and toss to coat evenly. Cover and refrigerate for at least 30 minutes. Add cilantro just before serving if using.

MAKE THE CAYENNE KALE CHIPS
Preheat oven to 150°C (300°F). Remove kale leaves from stems and wash thoroughly. Dry completely in a salad spinner then pat with paper towels. Any moisture creates steam which causes sogginess.

Tear kale into uniform 5cm (2-inch) pieces, discarding thick rib sections.

Place kale in a large bowl. Drizzle with olive oil and massage gently with your hands for 2 minutes, ensuring every surface is lightly coated but not dripping. Sprinkle with cayenne, garlic powder, and flaky salt. Toss to distribute evenly.

Spread kale in a single layer on a parchment-lined baking sheet. Pieces must not overlap or touch. Use two baking sheets if needed.

Bake for 20-25 minutes, rotating pan halfway through, until kale is completely dry and crispy. Remove immediately as they continue to crisp while cooling.

SET UP THE DREDGING STATION
In a shallow dish, whisk together flour, cornstarch, cayenne, paprika, garlic powder, onion powder, salt, and pepper.

Pour about 120ml (½ cup) of the buttermilk brine into a separate shallow dish.

Drizzle 2-3 tablespoons of buttermilk brine into the seasoned flour and mix with a fork. This creates craggy clumps that become extra-crunchy bits when fried.

BREAD THE CHICKEN
Remove chicken from brine and let excess drip off but do not shake or pat dry.

Dip chicken in seasoned flour, pressing firmly to coat all surfaces. Shake off excess.

Dip floured chicken in the buttermilk mixture, letting excess drip off.

Return to seasoned flour, pressing firmly and pressing craggy clumps onto the surface.

Place breaded chicken on a wire rack set over a baking sheet. Let rest for 10 minutes to allow the coating to adhere.

FRY THE CHICKEN
Pour vegetable oil into a Dutch oven to a depth of 5-8cm (2-3 inches). Heat over medium-high until a deep-fry thermometer reads 175°C (350°F).

Gently lower 2 pieces of chicken into the oil. Do not crowd the pot. Fry for 5-7 minutes per side, maintaining oil temperature between 160-175°C (325-350°F) by adjusting heat as needed.

Insert an instant-read thermometer into the thickest part. Remove chicken when it reaches 74°C (165°F) internal temperature.

Transfer fried chicken to a wire rack set over a baking sheet, not paper towels which trap steam. Season immediately with a light sprinkle of salt.

MAKE THE SPICY MAYO AND TOAST THE BUNS
Whisk together mayonnaise, hot sauce, cayenne, and garlic powder.

Melt butter in a large skillet over medium heat. Place buns cut-side down and toast until golden brown, 1-2 minutes.

ASSEMBLY
Spread spicy mayo generously on both cut sides of each toasted bun.

Place a piece of fried chicken on the bottom bun. Top with a generous mound of roasted jalapeño slaw, about 120ml (½ cup) per sandwich. Add pickle slices if desired.

Place the top bun on the sandwich and press gently. Serve immediately with cayenne kale chips on the side.