For Chicken: combine 2 tsps salt, 25g cornflour, and 1/2 teaspoon baking powder in a large bowl and whisk to combine. Make two slices into the chicken thigh to make sure no moisture builds up, as this can cause an oil explosion. Add chicken and toss until every surface is coated. Transfer to a wire rack set on a baking sheet. Transfer to the fridge and let rest, uncovered, for at least 30 minutes and up to overnight.
When ready to fry, preheat oil to 180 C in a pan large enough to hold the chicken. Combine remaining 75g cornflour, 1/2 teaspoon baking powder, the flour, and 2 teaspoons salt in a large bowl and whisk to combine. Add water and vodka and whisk until a smooth batter is formed, adding up to 2 tablespoons additional water if batter is too thick. It should have the consistency of single cream.
Add the chicken to the batter. Lift and allow excess batter to drip off, using your finger to get rid of any large pockets or slicks of batter. Carefully lower into hot oil. Fry, using a metal spider or slotted spatula to rotate and agitate the chicken as it cooks until evenly golden brown and crisp all over, about 15 - 17 minutes. Transfer to a paper towel-lined plate and season immediately with salt.
For The Sauce: combine gochujang, soy sauce, vinegar, sugar, garlic, ginger, and sesame oil in a large bowl and whisk to combine.
For the Kimchi: remove the stalks from the cabbage, then chop it into 4cm pieces and place in a large bowl. Sprinkle over the salt and massage it in with your hands.
Add the rest of the ingredients and stir to combine - you can use your hands but make sure you wear disposable gloves as the smell of the shrimp paste will stick to your hands.
Cover the bowl with cling film and leave to ferment at room temperature for 2–5 days. After 2 days fermentation you can transfer the kimchi to a sterilised kilner jar. Check the kimchi every day, letting out some gas and pressing the vegetables down into the brine.
When the kimchi tastes delicious, transfer the jar to the fridge. This will keep for up to three months. Serve dishes with rice, pickles & beer!