Pat the turkey breast dry with paper towels to remove surface moisture, then season it evenly with salt and pepper on all sides.
In a small bowl, whisk together the minced garlic, chopped sage, and olive oil to create a flavorful herb mixture.
Rub the herb-oil mixture all over the turkey breast, making sure to coat every inch evenly for maximum flavor infusion.
Place the turkey breast into the slow cooker, breast side up, and cover with the lid. Set to low heat.
Cook the turkey on low for about 4 hours, or until the internal temperature reaches 165°F (74°C) and the meat feels tender when gently pressed.
Once cooked, carefully transfer the turkey breast to a cutting board and let it rest for at least 10 minutes. This helps retain its juices and makes carving easier.
Slice the turkey breast against the grain into even slices, revealing a juicy, herb-infused interior with a slightly browned exterior.
Serve the slices immediately, enjoying the tender texture and aromatic herbs that make this dish a comforting centerpiece.