Melt butter in a large skillet over medium heat. Add onion and next 4 ingredients (onion, celery, bell pepper, and garlic), stirring constantly for 5 minutes. Stir in crawfish and next 7 ingredients (salt, black pepper,seasoning, thyme, onion powder, white pepper, hot sauce), cook 5 minutes. Stir in flour and cook stirring constantly for 2 minutes.
Stir in fish or chicken stock gradually and cook over low heat for 20 minutes, stirring occasionally. Stir in green onion and parsley and cook 3 minutes. Serve over hot cooked rice.
Recommended Sides: Perfect with a warm crusty bread and a salad.