Marinate the Salmon
In a bowl, whisk together Dijon mustard, olive oil, rosemary, garlic, honey, lemon zest and juice, salt, and pepper.
Pat the salmon dry and place it in a shallow dish or resealable bag.
Pour the marinade over the salmon, ensuring even coverage.
Cover and refrigerate for at least 30 minutes, or up to overnight for deeper flavor.
Prepare the Smoker or Grill
Preheat your smoker or grill to 400–450°F (high heat).
Soak wood chips in water for 30 minutes, then drain.
Set up your grill for indirect heat (coals or burners on one side, salmon on the other).
Add soaked wood chips to the smoker box or directly over the heat source.
Smoke the Salmon
Place the marinated salmon skin-side down on the cooler side of the grill.
Close the lid and smoke for 12–15 minutes (for 1-inch thick fillet), or until internal temperature reaches 135–145°F.
Optional: Brush with extra marinade during the last 2–3 minutes for a glaze.
Remove from heat and let rest for 5 minutes.