Step 1

Cut the onion into thick slices and place the slices in the bottom of the slow cooker.

Step 2

Rinse the turkey and set on top of onion slices.

Step 3

Mix poultry seasoning with extra black pepper, if desired. Then rub the turkey breast with seasonings. If possible, rub some under the skin of the turkey.

Step 4

Dot the turkey with the cubes of butter. If possible, put some butter underneath the skin.

Step 5

Cook on LOW for 3-4 hours. Check the temperature periodically. When it reaches the internal temperature of 165°F, it's done cooking.

Step 6

Let the turkey breast rest in the slow cooker on warm for 30 minutes. Then remove skin, slice, and serve!