Place the onions, carrots, celery and sage in the bottom of the slow cooker. Place your turkey breast on top of the vegetables.
Melt the butter, and add the poultry seasoning, garlic powder, paprika, salt and pepper. Whisk to combine.
Pour the butter and seasoning mixture over the turkey breast..
Cover and cook on low 6-7 hours. Remove the turkey from the slow cooker and let rest 10 minutes. Slice and serve!