In a large pot, add the sausage and brown over medium heat for 9 to 10 minutes, turning halfway. Remove sausage from the pot, and allow to cool.
Add the olive oil to the same pot, and sauté the onions, and garlic for 4 to 5 minutes over low heat until they begin to shimmer. Add the bell pepper, celery, Cajun seasoning, and cayenne pepper. Add the kidney beans, chicken stock, thyme, salt, pepper, and bay leaves. Slice the sausages and add them back to the pot. Bring the mixture to a boil, then reduce the heat to low, cover, and simmer for 45 minutes over low heat.
Meanwhile, cook yellow rice according to package instructions OR if making from scratch: add all the yellow ingredients to a pot on the stove, cover, and cook for 20-30 minutes on low heat until rice is tender. Alternatively, add all the ingredients to a rice cooker, and cook for 30 minutes. Fluff with fork when done.
To serve, add 1 cup of yellow rice to a bowl, and serve 1.5 cups of red beans to the bowl. Garnish with fresh herbs and red pepper flakes if desired. Enjoy!