Purée the onion, garlic, ginger, soy sauce, and brown sugar in a food processor. Pour over ribs and marinate for 8 hours.
Rinse the rice in a sieve under cold water, place in a small saucepan, and pour in enough water to cover rice and come to 1 inch above it. Bring to a boil and then reduce the heat and simmer for 15 minutes. turn off the heat and let the rice rest for 15 minutes without opening the lid.
Grill the ribs over charcoal until medium rare.
Serve on jasmine rice tossed with garlic butter, toasted macadamia nuts, and chopped scallions.