Heat 2 tablespoons butter in a heavy skillet over medium heat. Pat turkey breast dry with paper towels. Season with salt and pepper, then sear 3-4 minutes per side until golden brown. Transfer turkey to the slow cooker.
3 pounds turkey breast, 2 tablespoons butter, salt, black pepper
Add sliced onion and smashed garlic cloves to the slow cooker around the turkey breast. Tuck fresh thyme and rosemary sprigs under and around the turkey. Pour in 2 cups low-sodium chicken broth.
1 medium onion, 4 cloves garlic, 2 sprigs fresh thyme, 2 sprigs fresh rosemary, 2 cups chicken broth
Cover and cook on low for 4 to 5 hours. Check the internal temperature at 4 hours using a meat thermometer; turkey is done when it reaches 165°F in the thickest part. Remove turkey immediately to prevent drying out.
3 pounds turkey breast
Transfer turkey to a cutting board and tent with foil. Let it rest for 10 minutes to redistribute juices before slicing against the grain.
3 pounds turkey breast
Strain the cooking liquid into a saucepan, discarding solids. Whisk 2 tablespoons flour or cornstarch with ¼ cup cold water to make a slurry, then whisk into the hot liquid. Simmer 5-7 minutes until thickened. Taste and adjust salt as needed.
2 tablespoons flour, salt, black pepper, 0.25 cup white wine
