For the tea: Add the saffron threads to the white wine, and let the flavors steep for 10 minutes.
For the packets: Preheat the oven to 400 degrees F.
Place the fillets onto a plate, and stain each one with a few steeped saffron threads from the tea, and refrigerate for 15 to 20 minutes.
In a medium saute pan, pour in the remaining saffron tea, capers, carrots, orange zest, orange juice, and white wine. Bring the ingredients up to a simmer, and cook until the carrots are slightly tender, approximately 2 minutes. Stir in the butter, and season with salt, to taste, and remove the pan from the heat.
Tear off 4 pieces of foil or parchment paper large enough to wrap up each fish fillet and vegetables (not too tight.)
Place the whole green onion pieces in the center of the parchment. Lay a bed of carrot mixture over the whole green onions. Season the halibut with salt, and pepper, to taste, and place the fillets over the carrot mixture. Spoon the remaining sauce, and carrots over the fish, and fold up the parchment edges (not too tight), creating a sealed packet.
Set the packets on a sheet tray, and bake until the fish is just cooked through, approximately 10 minutes.
Once cooked, open the packets, and garnish the halibut with the green onion slivers.
In a pot, melt the butter over medium heat, add the green onion whites, and garlic, and sweat until tender. Add in the saffron threads, and stir.
Stir in the rice, ensuring the grains are well coated with the saffron-butter mixture.
Pour in the water, and stir to combine.
Bring the cooking liquid to a boil, cover, and reduce the heat to a simmer.
Cook the rice until the rice is fully cooked, about 25 minutes.
Season the rice with salt, to taste.
*Reserve the white portion of the green onion, if preparing the Saffron Rice recipe with this dish, recipe follows