Step 1

Stir together 6 cups warm water, sugar, and 1/2 cup salt in a large, lidded container until dissolved. Let cool. Place chicken in brine; cover and chill 8 hours.

Step 2

Drain chicken, and discard brine. Whisk together cornstarch, flour, chili powder, cornmeal, onion powder, garlic powder, and 4 teaspoons salt in a large bowl. Place buttermilk in a separate bowl. Working in small batches, dredge chicken pieces in cornstarch mixture, dip in buttermilk, and dredge again in cornstarch mixture. Place coated chicken pieces in a fine wire-mesh strainer, and shake off excess flour mixture. Place chicken in a single layer on 2 wire racks on rimmed baking sheets, and let stand 15 minutes.

Step 3

Meanwhile, place chorizo, onion, and jalapeño in a large skillet over medium. Cook, stirring occasionally, until chorizo is crumbled and browned and onions are softened, 8 to 10 minutes. Add greens and 1 teaspoon salt; cover and cook until tender, 3 to 4 minutes, stirring once halfway through. Stir in vinegar. Remove from heat.

Step 4

Stir together cayenne, brown sugar, onion powder, and garlic powder in a small bowl. Heat 1 cup grapeseed oil in a medium skillet over medium-high until hot, about 4 minutes. Remove from heat, and add spice mixture to oil, stirring to combine. Let cool 10 minutes. Transfer to a large heatproof bowl.

Step 5

Preheat oven to 200°F. Heat 1 inch of grapeseed oil in a large, heavy, high-sided skillet over medium-high to 360°F. Working in 3 batches, fry chicken, turning occasionally, until crispy and cooked through, 4 to 5 minutes. Transfer to bowl with spiced oil; toss to coat. Lift chicken from bowl; place on a wire rack set in a rimmed baking sheet. Sprinkle with 1/2 teaspoon salt. Transfer baking sheet to preheated oven to keep warm. Repeat procedure 2 times with remaining chicken and remaining 1 teaspoon salt.

Step 6

Divide braised greens and fried chicken among warm tortillas. Top with pickles.