Wash the baby bok choy thoroughly and cut them in half lengthwise
In a large bowl, dissolve the salt in about 2 cups of water. Submerge the bok choy halves in the saltwater, making sure they are completely covered. soak 20-30 minutes.
Rinse the bok choy under cold running water to remove excess salt. Drain them well and gently squeeze out any excess water. You want them to be slightly wilted but not soggy.
In a small bowl, mix together the minced garlic, grated ginger, gochugaru (or chili flakes), sugar, soy sauce, rice vinegar, and sesame oil.
Place the drained baby bok choy in a large mixing bowl. Add the green onions and the prepared seasoning paste to the bowl. Mix thoroughly
Gently toss everything together, ensuring that the bok choy is well coated with the seasoning paste.
Transfer the baby bok choy kimchi to a serving dish, and sprinkle with toasted sesame seeds if desired
Enjoy immediately, or you can let it sit at room temperature for 30 minutes to allow the flavors to meld a bit.