In a dish large enough to hold the fish fillets, add the pickling spice and several cups of water. Add the fish and ensure that the water covers the fillets. Set aside for 1 1/2 hours.
Prepare the grill or smoker for indirect cooking (one side of the grill has heat and the other side doesn't) Add the dry wood chips to the smoker box. Set the wood chips over the heat source on the grill and heat until it reaches about 250-275 degrees and begins to smoke. Add the fish fillets, skin side down to the opposite side of the grill that doesn't have the heat on. Smoke the fish for 2-2 1/2 hours until the skin has taken on an amber color and the flesh is cooked through. Transfer the fish to a baking sheet and let cool to room temperature.
Remove the skin from the fish and discard. Add chunks of the fish to a food processor and pulse 1-2 times. Add the mayonnaise, cilantro, lemon zest, juice of half the lemon, jalapeños, salt and pepper. Pulse several more times until the dip is smooth.
Transfer the dip to a food storage container and refrigerate overnight for the flavors to marry.
Serve with crackers and pickled onions, sliced jalapeños and fresh cilantro for garnish. Feel free to add a few dashes of your favorite hot sauce either to the dip itself, or to top off every luscious bite!