In a mortar and pestle or a food processor, combine black pepper, cilantro roots, garlic and coriander powder into a paste.
In a bowl, combine coconut milk, fish sauce, soy sauce, black sweet soy sauce, sugar, the paste and cornstarch. Pour marinade over the ribs, cover, and marinate overnight.
Preheat oven to 400°F.
Heat a nonstick pan on medium and add ribs to sear on all sides until browned. Transfer to a baking tray with a rack, cover with foil, and roast for 30 minutes.
Serve with sauce and rice on the side.
Rinse rice in cold water twice, then cover with water and soak for 1 hour. Drain and then wrap the rice well in a damp, fine cheesecloth.
Place in a steamer, cover, and steam for 15 minutes. Then flip it over and let it steam for 10 more minutes.
Turn off the heat and place the rice in a sealed container to keep warm until serving.
Combine sauce ingredients in a bowl and set aside.
