Place 4 boneless skinless chicken breasts in the slow cooker.
Add 8 ounces sliced mushrooms, 8 ounces softened cream cheese, 1 can cream of chicken soup, 1 package dry onion soup mix, and ½ teaspoon black pepper over the chicken.
Cover and cook on low for 5-7 hours or on high for 3 hours.
Shred the chicken and thoroughly stir the shredded chicken into the crock pot with the remaining items.
Cook 12 ounces large egg noodles according to the package directions.
Serve the chicken mixture over the egg noodles and enjoy!
Notes
Refrigerate the leftovers in an airtight container for up to 5 days.