Cut the fish into 1-inch strips. Toss the fish and the BBQ rub into a Ziploc bag, making sure that the fish is covered with the spice. Refrigerate overnight.
Combine all of the ingredients for the pickled veggies together in a covered container, and let them marinate overnight in the refrigerator.
Combine all of the ingredients for the slaw together in a large bowl. Transfer into a covered container and refrigerate.
Season the fish with salt and a squeeze of lime, and grill quickly on a well oiled grill over high heat, lightly brushing with a little oil once the pieces have been flipped.
Heat the tortillas on both sides on the grill. Put a spoonful of slaw on the tortilla, then some grilled fish, then top with the pickled veggies, sliced avocado and tomatoes. Enjoy!
