In a large deep skillet add cooking oil. I used olive oil. Allow pan to get hot
Dredge chicken thighs in flour seasoned with sea salt and pepper. place in pan over medium high heat, meat side down and allow to sear for 4-5 minutes until the chicken gets a good color. Turn over and do the same thing to the other side.
Remove chicken from pan, and set aside until needed.
Add peppers, onion, garlic and celery to oil and saute for 1 minute.
Add flour to pan and mix well. If more oil or flour is needed add it in now.
Turn heat down to medium and allow roux to cook and brown for 10-12 minutes, stirring constantly. Roux should turn medium brown. Be careful not to burn roux, you just want it to cook and get brown.
Add chicken stock and mix well, making sure all the roux gets incorporated into the stock.
Add stewed tomatoes, creole seasoning and Worcestershire sauce, mix well.
Reduce heat to low, add chicken and simmer, stirring occasionally for 1 hour.
Remove chicken and allow to cool.
Add sausage, okra and chopped parsley to gumbo, let it simmer for 20-30 minutes.
Bone chicken and pull meat apart. Add chicken to gumbo, and simmer 5 minutes.
Serve Gumbo over plain white rice.
Garnish with chopped green onions and file powder.