Preheat oven to 400°F. Line a sheet pan with parchment paper. Lay the filet skin side down on the parchment paper and season with salt.
Make the BBQ sauce. In a small sauce pan, combine all the ingredients over medium heat. Bring to a simmer and cook for 2 minutes occasionally stirring. If the sauce starts to stick to the bottom of the pan, turn down the heat. Transfer to a blender or using a hand blender, blend until the chipotle pepper and ingredients are a smooth, thick sauce.
Cook the fish. Pour ¾ of the chipotle bbq sauce over the fish and spread with a spatula or the back of a spoon. Cook the fish in a 400°F oven for 20 to 25 minutes or until and internal temperature of 145°F is reached. While the fish is cooking, prepare any taco toppings you want.
Make the fish tacos. Once the fish is cooked, the flesh of the fillet will easily lift for the skin with a spoon, fork, or knife. Cut into bite sized pieces and assemble your tacos.
For a fast short cut on the bbq sauce, you can take your favorite bbq sauce you already have and simmer it with the chipotle in adobo and 2 tablespoons of water then blend.