Mix together the slaw ingredients in a bowl, then cover and refrigerate until needed. May be made up to 1 day in advance.
In a blender or food processor, combine the sour cream (or base you are using) and the chilies. Pulse until fine. Adjust salt to taste. Cover and refrigerate until needed. Make up to 2 days in advance.
When you are ready to prepare the tacos, combine the shrimp with the olive oil and seasonings. Set aside while you preheat your grill to 350 F or warm your grill pan over medium heat. If using a grill basket, warm it on the grates to help with even heat distribution.
Grill the shrimp 2-3 minutes per side until pink and just cooked through. Remove from the heat. Warm the tortillas on the grill while the shrimp are cooking.
Assemble your tacos as desired, and enjoy immediately!