Preheat oven to 400°. In a small bowl, whisk curry paste, gradually adding coconut milk. Transfer 1/2 cup sauce to another bowl; set bowls aside.
Toast almonds in a small saucepan over medium heat until golden, 3 minutes. Stir in rice, reserved 1/2 cup sauce, 1/2 cup water, the coconut, and 1/2 tsp. salt. Bring to a boil, then reduce heat and simmer, covered, until rice is tender, 16 to 18 minutes.
Season halibut with remaining 1/4 tsp. salt and the pepper while rice cooks. Cut 4 pieces of parchment, each 12 by 14 in. Set a fillet in center of each, then mound asparagus and peas on top (some may roll off). For each packet, bring 2 opposite sides of parchment up over ingredients and fold several times to seal. Bring other sides up and fold to seal. Place packets, folded sides up, on a rimmed baking sheet. Bake until fish is just opaque (poke with a sharp knife to check), 10 to 15 minutes.
Microwave remaining 1/4 cup sauce to warm. Divide rice among 4 plates and top each with fish and vegetables from a packet, discarding extra liquid. Drizzle sauce over dishes and sprinkle with cilantro. Serve with lime wedges.
*Find in grocery stores' Asian-foods aisle.
Note: Nutritional analysis is per serving.