Whisk together 2 cups water, the maple syrup, salt and whole peppercorns in a bowl. Add the salmon, place a piece of plastic wrap over and place a plate on top to keep submerged. Refrigerate for 1 hour.
Remove the salmon from the brine. Pat the salmon dry with paper towels and place on a baking rack set over a baking sheet place in a cool, dry place (not the refrigerator) until the surface of the fish is dry and matte-like, 1 to 3 hours depending on humidity. A fan may be used to speed the process.
Combine the maple syrup, mustard and crushed pink peppercorns.
Prepare the ceramic cooker: Remove the grill grate and ceramic plate from the cooker. Scatter the soaked wood chips over the top. Adjust the cooker to maintain a temperature of 150 to 160 degrees F. This temperature should be maintained throughout the entire smoke. Put on the ceramic plate. Smoke until the thickest part of the fish registers 150 degrees, about 1 hour 30 minutes. Start brushing with the glaze every few minutes for the last 15 minutes of the smoking process.
Serve the salmon with the Brussles Sprouts Slaw.
Brussles Sprouts Slaw:
Whisk together the oil, vinegar, lemon juice, mustard, maple syrup, celery salt and some salt and pepper in a large bowl.
In a food processor with a grater attachment, shred the Brussels sprouts. (If you do not have a food processor you could grate by hand or cut very thinly with a knife.) Transfer to the bowl with the dressing. Add the radicchio and chives and toss to combine. Cover and refrigerate for at least 30 minutes before serving (to allow the sprouts to break down and soften). Add the walnuts before serving.