1. Combine first 8 ingredients in a small bowl, stirring with a whisk. Set aside.
2. Combine 1 cup water, rice, coconut milk, and 1/4 teaspoon salt in a medium saucepan; bring to a boil. Cover, reduce heat, and simmer 15 minutes or until liquid is absorbed. Remove from heat; let stand 5 minutes. Stir in cilantro.
3. Sprinkle fish evenly with remaining 1/4 teaspoon salt and pepper. Steam fish, covered, 8 minutes or until fish flakes easily when tested with a fork or until desired degree of doneness. Place 1/2 cup rice on each of 4 plates; top with 1 fillet. Drizzle each serving with 2 tablespoons sauce. Serve with lime wedges.