Season chicken with salt, pepper, and garlic. Place the chicken in the bottom of the slow cooker. Add butter, 1 cup chicken stock, and heavy cream. Cook on low for 4-5 hours or high for 3 hours. Remove chicken from slow cooker and chop or shred.
Add butter, 1 cup chicken stock, and heavy cream. Cook on low for 4-5 hours or high for 3 hours. Remove chicken from slow cooker and chop or shred.
Add 1/2 cup of chicken stock to the slow cooker. Add fettuccini and chopped broccoli. Leave the broccoli sitting on top, do not stir it in. (*if you prefer, you can pre cook your pasta and add in after broccoli is done cooking.)
Make sure the slow cooker is on high and let the pasta and broccoli cook for 30 minutes, or until desired doneness.
Stir in the parmesan cheese until melted. Add the chicken back in and stir to combine.
Serve warm with additional shaved parmesan, if desired.