Preheat oven to 400 degrees.
Mix all spices (salt through five spice powder together in a small bowl.
Cut rack in half and place both halves in a roasting pan. Rub spice blend over ribs to coat.
Mix together water, soy sauce, and rice vinegar and pour over ribs.
Cover with foil and roast 1½ to 2 hours, until meat is very tender. Check after 45 minutes and add water if the liquid has evaporated so the sauce will not burn.
While ribs cook, make slaw. In a large bowl, combine shredded red and green cabbage, cilantro, and green onion.
In a separate bowl, whisk together rice vinegar, sesame oil, peanut butter, sriracha, grated ginger, and minced garlic. Drizzle over cabbage mixture and toss to coat.
When ribs are tender and just starting to fall off the bone, remove from oven.
Switch oven to broil and broil ribs on the top rack about 5 minutes until crispy, being careful not to burn.
For each person, serve 3 ribs with ¾ cup slaw.