Prepare red crema, cucumber slaw, and citrus dressing by mixing each batch of ingredients in three bowls and whisking until all ingredients are incorporated. Set aside.
Preheat a grill or pan. Season the fish using Old Bay seasoning on both sides.
Place seasoned fish onto hot grill or pan and cook for about 2 minutes on each side. Fish should be done medium well. (Be sure not to overcook the Mahi or it will be dry.) Take off grill and keep warm.
Warm tortillas on hot sauté pan until heated through and brownish dark spots appear on both sides.
To build tacos: take one warmed tortilla and place one piece of mahi in the center. Add 1 teaspoon of red crema on top of mahi, top with cucumber slaw, 1 tablespoon of citrus dressing, and then one slice of avocado,