Brine the chicken: Brine the chicken by combining 1 cup of buttermilk, salt & pepper, 5-6 cloves of smashed garlic, chopped or leafed Thai basil, and cilantro. Place the chicken in the buttermilk brine in a ziplock and let it sit in the brine for 2-3 hours.
Pickle the daikon: While waiting for the chicken to brine, make pickled daikon by cutting the daikon into thin rounds. Then sprinkle salt over the daikon, let it sit for 10 minutes and wash the salt off. Combine ½ cup of hot water, ½ cup of rice vinegar and ¼ cup of sugar, whisk until the sugar dissolves and pour it right onto the daikon. Let it sit for at least 30 minutes—the longer the better.
Make the slaw: Shred the cabbage into thin strings, then chiffonade about 6 basil leaves, 3 cilantro stems and leaves, and 1 green onions and mix it all together. Season it with salt and pepper then ⅓ cup of kewpie mayo and 1 tbsp of rice vinegar.
Make the glaze: Combine ⅓ cup of pineapple juice, 1 tbsp of ketchup, 2 tbsp of brown sugar, ½ cup of rice vinegar, 3 cloves minced garlic, 1 tsp minced ginger. Bring it to a boil, turn it down to a simmer and leave it cooking for a few minutes. Make a slurry by combining 1 tsp of cornstarch and 1 tbsp of water then and add slurry to thicken the glaze. When the chicken is done brining, take it out and pat dry.
Cook the chicken: Spray grill or grill pan with cooking oil or wipe some neutral cooking oil, once the pan is smoking place the chicken skin side down first then flip after 5 minutes and cook for another 3-5 minutes. then glaze the chicken thighs with the sweet and sour glaze after it's done cooking. Toast bread on the same grill or grill pan as the chicken.
Assemble the sando: Bottom bun, add the daikon rounds, glazed chicken, slaw. On the top bun, slather with kewpie mayo.
