If using dried peas, place them in a large saucepan and add water to cover. Bring the mixture to a boil, reduce the heat and cook until the peas are tender, about 30 minutes.
Heat the oil in a heavy skillet over medium high, add the garlic, chile, and onion and saute until soft. Add the rice and continue to saute until the rice browns slightly. Stir the peas into the rice.
In a large saucepan, combine the coconut milk with 3 cups of the reserved bean liquid. (If you do not have enough bean liquid, add water to make up the difference.) Bring to a boil and add the rice mixture. Bring the liquid back to a boil and immediately reduce the heat to low. Cover and simmer until the liquid is absorbed and the rice is tender, about 20 to 25 minutes.
Fluff the rice with a fork, stir in the green onions, and serve.
