In a large Dutch oven or pot, heat 2 tablespoons of the vegetable oil over medium-high heat. Add the sausage and brown until cooked through, about 10 minutes. Remove the sausage to paper towels and allow to drain. Brown the chicken in batches, removing to a paper towel to drain.
Add the rest of the oil to the pot over medium-high heat . When the oil is smoking add the flour and stir constantly until mixture is dark brown, about 5 minutes. Add the onions, bell pepper, and celery and cook until the onions are translucent. Stir often for about 10 minutes. Add garlic, salt, cayenne pepper, bay leaves, oregano, sausage, chicken, and black-eyed peas then stir for 2 more minutes.
Stirring, slowly add the chicken stock until well combined. Bring the mixture to a boil then reduce the heat to medium-low and cook uncovered, stirring occasionally, for one hour. Skim off any fat that rises to the surface.
Add the shrimp, green onions, parsley, and file powder and stir until well combined. Serve over rice and garnish with the extra chopped chives and parsley. Season with Hot Sauce.