In a large bowl, whisk together the olive oil, vinegar, honey, dijon mustard, garlic, herbs, and seasonings until evenly combined.
Place the tenderloins in a gallon-sized Ziploc bag with the marinade. Close the bag and toss to coat. Cover and refrigerate for at least 1 hour, (or up to 6 hours), to allow the flavors to infuse with the poultry.
Add poultry and marinade to the slow cooker. Pour chicken broth over meat, then place the lid on your crock pot. Cook the turkey breast tenderloins on low for 6-8 hours, checking the turkey tenderloin temp after 4 hours.
Turkey tenderloins are done when a thermometer inserted into the thickest part of the meat registers 165 degrees Fahrenheit. To avoid overcooking, remove turkey when the internal temp reaches 163°F.Tent the turkey tenderloins with foil and allow them to rest for 10 minutes before slicing and serving.
Notes
If you are in a hurry, mix the marinade and pour it directly into the slow cooker pot along with the turkey tenderloin.Roasted turkey tenderloins will last up to 4 days stored in a sealed container in the refrigerator. They also are great to freeze! Once cooled transfer them to a freezer-safe zipper bag, and keep them stored for up to 3 months.