The populations of wild Atlantic salmon are so depleted that they are no longer commercially viable. So all Atlantic salmon are farm-raised, and since the largest farms are in Norway, Norwegian salmon is now the common name for Atlantic salmon. Although farm-raised Atlantic salmon has its problems, it is the salmon that grill-smokes the best. We find Pacific salmon too lean to hold up to smoking on a grill. Look for a thick fillet with full (but not dark) color, which indicates a high enough fat content to keep the fish moist during smoking. To enhance its moisture, the fillet is brined for a few hours. Then it’s rubbed with a smoke-flavored rub, and cooked gently beside a smoky fire.
Put the salmon in a jumbo (2-gallon) zipper-lock bag. If you only have 1-gallon bags, cut the fish in half and use 2 bags. Add the brine to the bag(s), press out the air, and seal. Refrigerate for 3-4 hours.
Mix all but 1 tablespoon of the Smokin’ Rub with the dried dill and onion powder and set aside.
Soak the onion slices in ice water.
Heat a grill for indirect low heat, about 225 degrees, with smoke. Drain the wood chips and add them to the grill.
Remove the salmon from the brine and pat dry with paper towels. Discard the brine. Coat the fish with 1 tablespoon of the oil and sprinkle the meaty side with the rub that has dried dill in it.
Lift the onions from the ice water and pat dry. Coat with 1 tablespoon of the oil and sprinkle with the remaining 1 tablespoon rub. Set the fish and onions aside to rest for 15 minutes.
Brush the grill grate and rub well with oil. Place the salmon, flesh side down, directly over the heat and grill for 5 minutes until the surface is golden brown. Using a large fish spatula or two regular spatulas, turn the fish skin side down and position on the grill grate away from the fire. Put the onion slices over the direct fire. Close the grill and cook until the salmon is firm on the outside, but not dry, and resilient in center, about 25 minutes. When done, moisture will bead through the surface when the fish is gently pressed. It should not fully flake under pressure. Turn the onions once during the cooking time.
While the salmon is cooking, remove the leaves from the fresh dill and chop coarsely. Mix with the lemon zest, garlic, salt, pepper, and remaining 2 tablespoons olive oil.
When the salmon is done, transfer to a platter using a fish spatula. Let rest for 5 minutes to finish cooking. Surround with grilled onion slices and scatter the fresh dill mixture over the top.