Banana leaves can be found in most Latin American or Southeast Asian markets - usually, they're found in the freezer section. They have a pleasant scent that smells somewhat like tea, and wrapping fish in banana leaves and steaming them imparts some of the banana leaf flavor in them. Plus, the banana leaf acts as a convenient little packet for holding other ingredients with the fish, and keeps the fish from falling apart or losing delicious juices.
This is a simple recipe. Choose any firm-fleshed fish - tilapia, salmon, and catfish are good choices. Check whether the fish is sustainable first, though. You can choose to make a paste from garlic and fresh herbs such as cilantro and mint, or you can use a prepared paste such as red Thai curry paste, and spread either of these on the fish before sealing the banana leaf packet. Or you can add some coconut milk and ginger, or some fresh mushrooms, scallions, and Thai basil. This recipe leaves a lot of room for experimentation, so be creative. In the photos above, we spread a little shrimp paste on our tilapia before wrapping up the packet.
(Images: Kathryn Hill)