In a large heavy skillet, add the vegetable oil and butter over medium heat

Add the Andouille sausage and cook until crisp (about 5 minutes), stirring constantly

Add onion, celery, peppers and seasonings to the pan

Stir well and cook until browned (about 10 minutes) scraping the pan bottom as needed

Add the chicken and raise the heat to high and cook 1 minute, stirring constantly

Stir in the rice and garlic and cook 5 minutes, stirring and scaping the pan bottom occasionally

Add the chicken stock, stirring well

Bring the mixture to a boil, reduce the heat and simmer until the rice is tender but still has a little bite to it (about 20 minutes), stirring occasionally toward the end of the cooking time