1. Cut chicken thighs into bite-sized pieces. Place them in a bowl and pour over the buttermilk with a pinch of salt. Marinate for at least 1 hour or overnight in the refrigerator.

2. In a small saucepan, combine gochujang, soy sauce, brown sugar, minced garlic, and rice vinegar. Simmer for 5 minutes until thickened. Let cool.

3. In a shallow bowl, mix together cornstarch and flour. Dredge marinated chicken pieces in the dry mix, pressing to coat each piece.

4. Heat oil in a deep skillet to 350°F (175°C). Fry chicken in batches until golden brown and crispy. Drain on a wire rack or paper towel.

5. While hot, toss the crispy chicken in the gochujang sauce until evenly coated.

6. Steam bao buns according to package directions (typically 6–8 minutes).

7. Assemble the buns: Fill each with pickled carrots and cucumbers, then add saucy chicken. Top with scallions, cilantro, and sesame seeds. Serve immediately.