Rinse salmon; pat dry with paper towels. Sprinkle salmon with salt and pepper. In a 4-quart slow cooker combine leeks and the water. Place salmon on top of leeks, cutting to fit if necessary.
Cover and cook on low-heat setting for 1 3/4 to 2 hours or until salmon flakes easily when tested with a fork. Remove salmon from cooker; discard leeks and cooking liquid. Cool salmon slightly. Using a fork, coarsely flake salmon.
In a medium bowl combine cream cheese spread and 3 tablespoons of the chives. Stir in salmon. Cover and chill for 2 to 8 hours.
To serve, mound salmon mixture onto endive leaves. Sprinkle with the remaining 1 tablespoon chives. If desired, serve with lemon wedges.