Heat 2 tablespoons olive oil in sauté pan over high heat; add peppers, onion, celery and garlic. Sauté until onions are soft. Add etouffée sauce, and reduce to a simmer.
In another skillet, heat 1 tablespoon olive oil over medium-high heat. Sprinkle fillets with Cajun seasoning. Place into skillet, and sauté for approximately 4 to 5 minutes.
Turn fillets over, and gently pour etouffée sauce over fillets. Reduce heat to low; simmer approximately 5 minutes or until catfish is cooked through.
Serve over rice.