In a small bowl, combine smoked paprika, garlic powder, onion powder, cayenne, thyme, sea salt, and black pepper.
Pat the redfish fillet dry with paper towels and coat both sides evenly with the spice mixture.
Heat the avocado oil in a large cast-iron skillet over medium-high heat until it begins to shimmer.
Place the fish in the skillet and sear for 3 to 4 minutes per side until a dark, flavorful crust forms.
Remove the fish from the pan and set aside on a plate.
In the same skillet, add the diced onion, green bell pepper, and celery, sautéing for 3 minutes until tender.
Pour in the heavy cream and add the crawfish tails, simmering for 2 minutes until the sauce is slightly thickened.
Serve the redfish topped with the warm crawfish cream sauce and a sprinkle of fresh parsley.