Spray the slow cooker crock with nonstick cooking spray, and pour the water into the bottom of the crock.
Placed the lemon slices and fresh herbs around the bottom and sides of the crock.
Combine the onion powder, garlic powder, salt, thymes leaves, and black pepper together to make a rub.
Take ½ of the butter and rub under the skin of the turkey. Next rub half of the dry seasoning under the skin.
Using the last half of the dry seasonings, be sure to cover all sides of the turkey breast.
Cook on low for 6 hours or until the internal temperature reaches 165 degrees.
For crispier skin, preheat the broiler of the oven. Transfer the turkey to a baking sheet. Place under the oven broiler for 5 to 10 minutes.
To make the gravy, melt butter in a skillet over medium heat. Whisk in the flour. Reduce heat to low. Measure the pan drippings and add enough chicken stock to equal a total of 4 cups liquid. Slowly add the liquid, stirring constantly, until the gravy is smooth. Add the seasonings and simmer, stirring often, until the gravy has thickened, approximately 5 minutes.
Make sure that the internal temperature of your turkey breast reaches 165 degrees.