Place eggs in a pot, cover with cold water, and bring to a boil. Simmer 10–12 minutes, then cool in an ice bath. Peel and halve each egg.
Mash yolks until smooth, then add mayonnaise, mustards, lemon juice, Cajun seasoning, paprika, salt, and pepper. Spoon or pipe into egg whites.
Heat butter or oil in a pan. Sear sausage slices until crisp, then cook shrimp with Cajun spices and garlic powder until pink.
Melt butter, sauté garlic, and stir in lemon juice, hot sauce, Old Bay, Cajun seasoning, smoked paprika, and cayenne. Simmer 3–5 minutes.
Add one shrimp and one sausage slice on each egg half, drizzle with seafood boil sauce, and sprinkle with parsley and paprika.
