In a large Dutch oven over medium-high heat, brown the andouille sausage slices for 5-6 minutes until they develop a nice caramelized color. Remove and set aside.
Add vegetable oil to the same pot. Sauté onion, bell peppers, and celery for 6-7 minutes until softened (this is your "holy trinity" of Cajun cooking!).
Add garlic and cook for 1 minute until fragrant.
Stir in Cajun seasoning, smoked paprika, cayenne pepper, thyme, and bay leaves. Cook for 1 minute to bloom the spices.
Add diced tomatoes, tomato paste, and chicken broth. Stir well, scraping up any browned bits from the bottom of the pot.
Return the sausage to the pot and add the cubed potatoes. Bring to a boil, then reduce heat to medium-low.
Cover and simmer for 25 minutes until potatoes are tender.
Add okra (if using) and kidney beans. Simmer uncovered for another 10 minutes.
Remove bay leaves and season with salt and pepper to taste. Garnish with sliced green onions and serve over white rice with hot sauce on the side. Store leftovers in the fridge and reheat the next day for maximum flavor!