Heat a large, heavy skillet over medium-high heat. Add 1 tablespoon olive oil and chicken breast, browning on all sizes. Remove chicken and keep warm.
To the hot skillet, add additional oil if needed and vegetables (onion, bell pepper, and celery). Cook vegetables until softened (about 3 to 5 minutes), stirring often.
Return the chicken to the skillet. Also add the sausage, chicken broth, tomatoes, and remaining seasoning. Bring to a boil.
Cover and reduce heat, cooking about 10 minutes or until chicken is cooked through, stirring as needed.
Remove lid. Add cauliflower and cook for an additional 5 minutes or until tender.
Adjust seasonings and serve.