In the same pan, add all remaining ingredients (butter, cream, broth, garlic, black pepper, and rosemary) and stir to combine, making sure to break up any bits and pieces left in the pan from cooking the chicken to combine those into the sauce as well.
Stirring occasionally, let the sauce simmer and reduce for about 5 minutes.
Add the chicken back to the pan and ladle the sauce over it. Allow it to warm in the simmering sauce for 1 min.
Remove the pan with the chicken and creamy rosemary sauce from the heat and serve over pasta, rice, zoodles, or cauliflower rice! Optional: Top with a few sprigs of fresh rosemary for garnish.