Remove the outer plastic wrapping and discard. Throw away the gravy packet.
Place the frozen turkey breast into the insert of your Crock-Pot. There will likely be a twine wrapping around the breast to hold it together. You will cut this away after it is cooked.
In a microwave-safe, 2-cup capacity measuring cup, (or a microwavable small bowl) melt the butter.
Add the flour and microwave for one minute. Whisk.
Whisk in the wine. Microwave for one additional minute. The mixture will bubble up and thicken.
Whisk in the turkey broth and seasonings. Pour the gravy over the turkey breast.
Cover with the lid and cook on LOW power for 8 hours.
Check the the center of the turkey breast with an instant read digital meat thermometer. It needs to be a minimum of 165 degrees F to be safe to eat!
Carefully remove the turkey breast to a cutting board. Use kitchen shears to gently cut away the twine. And also, remove and discard any visible fat.
Strain the gravy and discard any fat that might be floating in it.
Return the gravy to the slow cooker insert. Slice the juicy turkey breast and return it to the gravy.
Continue to cook on low until the turkey and gravy are heated through and you are ready to eat.