Preheat the oven 375 degrees Fahrenheit.
Slice each piece of cod into about 1 inch wide by 2 inch long pieces.
In a medium bowl, whisk the egg until the yolk is completely broken up.
In a second bowl, combine the flour, breadcrumbs, spices and salt.
Dip each piece of cod into the egg, then immediately into the breadcrumb mixture and place on a baking sheet lined with parchment paper. Repeat until all fish has been used.
Add to the preheated oven for 10-14 minutes, or until the fish is cooked through and easily flakes with a fork.
Meanwhile, in a medium bowl, combine the shredded cabbage, lime juice, cilantro, mayo and salt. Massage with your hands and let sit to marinate.
In a second bowl, whisk together the ingredients for the dressing, adding enough water so it isn't too thick. Add just 2 tablespoons at a time so it doesn't get too watery too quickly.
Add enough oil to a pan to light coat the bottom, about 2-3 tablespoons. Once hot, add each piece of cod (leaving enough space between each) and cook on each side for 1-2 minutes or until golden brown.
Transfer to a wire rack while you finish all of the fish.
Assemble the tacos with a warm tortilla, fish, cabbage slaw, pico de gallo and the spicy tahini dressing.
