In a large skillet over medium heat, cook the bacon to your preferred level of doneness.
Remove the bacon to a paper towel-lined plate.
Season the chopped chicken with salt and pepper, then add to the hot bacon grease and cook until browned all over and chicken reaches an internal temperature of 165F (approximately 6-8 minutes).
Meanwhile, prepare the pasta according to package directions. Drain but do not rinse.
Remove the chicken to a clean plate as you prepare the ranch sauce.
Wipe out the skillet and add the chicken broth. Bring to a simmer, then add the sour cream and cream cheese and stir as the cream cheese melts. Add a bit more broth or milk to achieve a smooth consistency that coats the back of a spoon.
Season with ranch seasoning, to taste.
Chop the bacon and add all but a couple tablespoons to the skillet, along with ¾ cup of the cheddar cheese and chicken. Stir to combine.
Add the pasta and stir to coat.
Sprinkle on remaining cheese, bacon and the green onions before serving.