Place butter, Cajun seasoning, cayenne, liquid smoke, paprika, parmesan cheese, and parsley in a sauté pan over medium to medium-high heat; melt, taking care not to burn butter. Add onion and sauté until translucent, 3 - 5 minutes. Add garlic and sauté 1 minute. Add oysters and cook for 5 - 7 minutes, until oysters plump and begin to curl around the edges.

Serve at once, with plenty of crusty French bread for soaking up the sauce.