For an extra layer of flavor, consider grilling the tortillas lightly before filling them. Adjust the amount of cayenne pepper in the slaw and blackened seasoning to control the spice level. Feel free to add other toppings such as crumbled cotija cheese, a drizzle of crema, or your favorite hot sauce. For a lower-carb option, serve the blackened shrimp and slaw over a bed of lettuce or in lettuce wraps instead of tortillas.