Heat oil in a large stockpot over medium high heat. Add the sausage and sear it, about 3 minutes. Remove sausage from pot and set aside.
Add peppers, onion and celery and cook for three minutes, or until softened and fragrant. Add garlic, tasso ham (if using,) bay leaves, salt, pepper and cajun seasoning and cook for 2 minutes.
Drain beans and rinse. Add chicken stock, sausage and beans and bring to a boil. Decrease heat to a simmer, and allow to cook for 2-3 hours or until beans are softened. Remove from heat and serve with cooked rice.