Heat a large pan of oil on medium high, add the pork to the pan and season with pepper. Stir fry until browned 5-8 minutes, then remove the pork from the pan with a slotted spoon and set aside.

Whisk together all the sauce ingredients in a small bowl and set aside

Combine the corn starch and the chicken broth and set aside

Add the onion and bok choy whites to the pan with the garlic and fry on medium high for 30-60 seconds, then add the sauce and bring to a boil.

Reduce heat to medium and add the pork back to the pan with the greens and kimchi. Toss to coat and cook for 1 minute,

Add the udon and chicken broth to the pan, bring the liquid to a boil and break apart the noodles, tossing to fully coat everything in the sauce, then serve.