Place onion, baby bok choy and crushed red pepper flakes in a well-oiled slow cooker then arrange cutlets on top.
In a medium bowl, whisk together next 8 ingredients (garlic through gingerroot); pour mixture over roast in slow cooker.
Cover and cook on LOW for 8 hours or until cutlets are fork-tender. Stir in chopped cilantro and green onions (if using); serve.