How to Make It
Preheat the oven to 350°. In a cup, cover the tea with the boiling water and let steep for 5 minutes. Strain the tea and let cool to room temperature.
Cut out eight 14-inch squares of brown parchment paper. Lay a parchment square on a work surface and set a cod fillet in the center. Make 4 deep, evenly spaced slashes in the cod. In each slash, place a sage leaf and 1/4 teaspoon of the furikake. Pour 1 tablespoon of tea over the cod and season with salt and pepper. Gather the paper up and around the fish and twist, then tie with kitchen string. Set the packet on a large rimmed baking sheet. Repeat with the remaining fish, sage leaves, furikake, tea and seasonings.
Bake the packets in the center of the oven for about 30 minutes, until simmering gently. Transfer the packets to plates and serve, letting guests untie and carefully open them at the table.
Furikake, the Japanese seaweed and sesame seasoning for rice, is available at Asian markets and specialty food shops.