Whisk together all of the ingredients for the sauce and set aside.
Cut chicken into smaller chunks and set in a bowl with salt, pepper, egg, and buttermilk. Allow to marinate for at least 1 hour.
Mix together the flour, potato starch, and baking soda in a large bowl. Remove chicken pieces from the buttermilk, making sure to shake off any excess liquid, and coat in the mixed flour dredge.
Add oil to a large stockpot and heat to 350F. Cook the chicken bites, working in batches, for 5 minutes or until golden brown. Remove with a slotted spoon and set on a baking sheet lined with a cooling rack or paper towels while you fry the remaining batches.
Heat up the gochujang sauce until thickened while the chicken bites fry.
Add all the chicken bites to a large bowl or serving platter, pour over the gochujang sauce and mix to combine. Serve immediately with chives and sesame seeds.
Recipe by Slice of Jess at https://sliceofjess.com/gochujang-korean-fried-chicken-recipe/