Rinse the catfish fillets and pat them dry with paper towels.
In a shallow dish, combine cornmeal, flour, Cajun seasoning, salt, and pepper.
Pour the buttermilk into another shallow dish.
Dip each catfish fillet into the buttermilk, then dredge in the cornmeal mixture, pressing firmly to adhere the coating.
Heat the vegetable oil in a large, heavy skillet over medium-high heat.
Fry the catfish fillets in the hot oil for about 4-5 minutes on each side, or until golden brown and cooked through.
Remove the fillets from the oil and drain on paper towels.
Serve hot with lemon wedges and garnish with chopped parsley.
Notes
Ensure the oil is sufficiently hot before adding the fillets to prevent them from becoming greasy. Adjust seasoning to your taste preference if desired.