How to Make It
Fold a 30- x 18-inch piece of parchment paper in half lengthwise; fold in half again crosswise (short end to short end) to create a 4-layer-thick piece. Place folded parchment in bottom of a 6-quart slow cooker, letting ends extend partially up sides.
Place half of lemongrass, fennel, and scallions in an even layer on parchment in slow cooker. Add water and wine. Sprinkle salmon with salt and pepper; place on lemongrass mixture. Top salmon with remaining lemongrass, scallions, and fennel.
Cover and cook on HIGH until salmon flakes easily with a fork, 1 to 2 hours. Using parchment paper liner as handles, lift salmon from slow cooker, allowing liquid to drain off. Discard mixture in slow cooker.