Cook pasta according to package directions, drain and set aside.
Season the catfish and shrimp with 2 tablespoons of the blackening spice.
Sauté the sausage for 3 minutes; add celery, onions and peppers; and sauté another 5 minutes until translucent. Add catfish and shrimp, and sauté 4 minutes or until cooked through. Add chicken stock, and reduce by half. Add cream, pasta, remaining seasonings and 1 tablespoon blackening spice. Stir in ½ of green onions and ½ of parsley.
Garnish with remaining parsley and green onions when serving.