In a food processor, process the sour cream, chipotles, oil, vinegar, lime zest, lime juice and agave until smooth; season with salt and pepper. Transfer to a large bowl, add the cabbage, onion and cilantro and toss to coat.
Preheat a grill, cast-iron skillet or griddle over medium-high. Season the fish with salt, pepper and the spices. Grease the outdoor grill grates or spray the skillet or griddle with cooking spray. Cook the sh until just opaque in the centers, about 4 minutes per side. Transfer to a platter; squeeze the lime over the sh. Break up with a spatula.
In a large, dry skillet over high heat or directly over the open ame on a gas stovetop or on the grill, cook the tortillas until charred in spots, turning occasionally, about 2 minutes.
Fill the tortillas with the fish, slaw and toppings of choice.