Add the green pepper, okra, chile powder, paprika, fil, oregano, thyme, cayenne and white pepper. Season with salt and cook over moderately low heat, stirring, until fragrant, 5 minutes. Stir in a ladleful of the liquid in the stockpot, scrape up the browned bits and transfer to the gumbo in the pot. Simmer, stirring, for 1 hour.