Before you cook your turkey breast in the crock pot, fill the crock pot with any vegetables or seasonings you want to use, such as onions, thyme, and garlic. Then, place your turkey breast in the crock pot and cover it with a lid. If the turkey breast weighs 2 pounds, leave it in the crock pot for 5 hours. If it’s 4 to 6 pounds, let it set for 6-7 hours. If it’s 8 to 10 pounds, let it set for 8-9 hours. For tips on serving your turkey breast, like why you need to rest it after cooking, keep reading!