Turn the Ninja Foodi on high sear/saute. Add in olive oil and when heated add in the diced onion, green pepper, celery. Add in seasoning blend and saute for about 2 minutes. Add in minced garlic and continue to saute for about 3 minutes.
Deglaze the pan with the chicken stock and make sure nothing is stuck to the bottom of the Ninja Foodi. Add in rootbeer, fire roasted tomatoes, sliced Andouille sausage, whole chicken thighs, and frozen or fresh okra.
Combine the vegetable oil and the flour in a 6" Fat Daddio cake pan and stir until a thin paste is formed. Cover with a silicone lid or foil and place on the rack in the high position over the gumbo.
Put the pressure cooker lid on and set the valve to seal. Pressure cook on high for 10 minutes and when finished, do an immediate release.
Remove the rack and uncover the roux. Pour the roux into the gumbo, but do not stir.
Rinse 2 cups of white rice under water until it runs clear and place in a 6" Fat Daddio pan and add 1 3/4 cups of water. Place on the rack in the high position uncovered over the gumbo. Put the pressure lid on and turn the valve to seal. Pressure cook for 2 minutes and allow to natural release for 4 minutes.
After the 4 minutes of natural release, manually release the remaining pressure. Remove the lid and the rack with the rice. Fluff the rice with a fork and cover loosely to keep warm
Stir the gumbo and add the shrimp. Make sure the shrimp are covered with the gumbo and close the TenderCrisp lid and allow to sit for 5 minutes. Leave the Ninja Foodi off. The residual heat will cook the shrimp.
Serve over rice and enjoy!