Heat a large, heavy-bottomed skillet over high heat. Add the olive oil and swirl to coat the bottom of the skillet. Once the pan is hot, add the sausage, allowing it to sear for 1-2 minutes before flipping to sear the other side. Remove sausage from the skillet and set aside.

Return the skillet to medium-high heat. Add one more tablespoon of olive oil, swirl to coat, and add the chicken in a single layer. Sprinkle with salt, pepper, and 1 tablespoon of Cajun seasoning. Cook the chicken, undisturbed, for 2 minutes before stirring. Continue to sauté for 3-4 minutes, stirring often, until cooked through. Transfer to a clean plate and set aside.

Return the skillet to medium heat. Add additional olive oil if needed, then add the minced onion. Cook for 4-5 minutes until soft and translucent. Add the minced garlic, remaining Cajun seasoning, dried rosemary, and a pinch of salt. Cook while stirring continuously for 1 minute.

Add the chicken broth and drained kidney beans to the onions. Bring to a simmer, then add the sausage and chicken back to the skillet. Mix well to combine and cook for 1-2 minutes or until heated through. Season with salt and pepper to taste, and serve with cooked rice if desired.