Preheat oven to 400°F. Zest half of the lime and extract juice, set aside.
Bring 1/2 cup of coconut milk and 1 cup water to a boil. Add rice and turn to simmer. Cover and steam for 18 minutes. Let rest 5 minutes. Fluff with fork and add half of the chopped cilantro leaves. Stir to mix and keep warm.
In a small bowl whisk together the remaining coconut milk, Thai green curry paste, remaining chopped cilantro, lime juice and zest. Set aside.
In a large baking dish coated with cooking spray or oil, add halibut and drizzle with some oil. Massage oil over fish and season with salt and pepper.
Top each Alaska halibut filet with the coconut curry sauce. Bake uncovered for 12 to 15 minutes, until Alaska halibut flakes easily when tested with a fork. Drizzle with pan coconut curry sauce and serve over coconut rice.