In a large bowl, combine one-half cup of soda water, one-half cup of fresh lime juice, one-half cup of water, two tablespoons of salt, two tablespoons of brown cane sugar, and one tablespoon of chili powder. Set aside a one-quarter cup of the marinade. Add the cod strips to the bowl containing the remaining marinade, and set aside.
In a separate bowl, mix the reserved quarter cup of marinade, one cup of black beans, and one chopped, seeded jalapeno pepper. Set aside.
In another large bowl, combine one-half cup each of mayonnaise and sour cream, one tablespoon of chili powder, one teaspoon of cider vinegar, one-half teaspoon of salt, one teaspoon of granulated sugar, and one tablespoon of chopped green onions. Add one package of coleslaw and mix until coated. Set aside.
In a shallow dish, sift one cup of Bisquick with one tablespoon of chili powder.
Remove the pieces of cod from the marinade and coat them in the Bisquick mixture. Heat the oil in a deep-sided skillet to 375°F.
Place the coated fish into the skillet without crowding. Cook for six minutes on each side or until golden brown. Transfer the cod strips to a wire rack.
Heat the black bean mixture and the one-quarter cup of reserved marinade in separate pots over medium heat.
Assemble the tacos by placing the cod strips into the center of the tortilla; top with the coleslaw, and black beans mix.
Drizzle a little of the heated marinade over the fillings.
Serve and enjoy!