01 - In a medium saucepan, bring water and 1 tsp salt to a boil. Gradually whisk in the grits. Reduce heat and simmer, stirring frequently, until thick and creamy (20-25 minutes for stone-ground grits). Stir in 3 tbsp butter, milk or cream, and cheddar cheese. Keep warm over low heat, stirring occasionally.
02 - In a small bowl, combine smoked paprika, garlic powder, onion powder, thyme, cayenne, oregano, salt, and black pepper.
03 - Pat catfish fillets and shrimp dry. Coat both sides of the catfish and shrimp with the blackening spice mix, pressing gently to adhere.
04 - Heat a large cast iron skillet over medium-high heat. Add sliced andouille sausage and cook until browned and slightly crispy, about 3-4 minutes. Transfer to a plate and keep warm.
05 - Add 1 tbsp olive oil and 1 tbsp butter to the skillet. When hot and shimmering, add the catfish fillets. Cook for 3-4 minutes per side until blackened and cooked through. Remove and keep warm.
06 - Add remaining olive oil and butter. Sauté shrimp for about 2 minutes per side until opaque and lightly blackened.
07 - Spoon the creamy grits evenly onto plates. Top with blackened catfish, shrimp, and sausage slices. Sprinkle with chopped parsley and serve with lemon wedges.