Melt the butter in a large skillet over medium heat. Sauté the onions until translucent.
In a 6-quart slow cooker, whisk together the cream of chicken soup, gravy mix, and chicken broth. Add the chicken breasts and sautéed onions. Cover and cook on low for 3 hours.
Remove the chicken from the slow cooker and shred into bite-sized pieces. Return the shredded chicken to the slow cooker.
Add the heavy cream and ground black pepper. Mix well. Taste and season with additional salt if desired.
Serve over cooked white rice and garnish with fresh parsley.
Recipe Tips
Don't skip trimming the chicken breasts before they go into the crockpot. Excess fat and skin will render in the gravy over three hours and can leave it greasy.
Shred the chicken right in the slow cooker rather than on a cutting board. The shredded pieces soak up more of the gravy while it's still warm.
Taste before adding extra salt. Between the canned soup, gravy mix, and broth, this recipe is often seasoned enough on its own