Prepare the Chicken: Start by ensuring your chicken is thawed if previously frozen. Remove the skin and trim off any excess fat to keep the dish light. Dry the chicken thoroughly with paper towels to allow the seasoning to stick better.
Season the Chicken: Mix the dry spices in a small bowl.Rub the spice blend over the entire chicken, inside and out. Be sure to season the cavity of the chicken for maximum flavor.
Wet marinade: Spread the Dijon mustard over the seasoned chicken, followed by the lime juice and apple cider vinegar. Marinate in the refrigerator for 30 minutes to 4 hours.
Tuck the wings under the body and tie the legs together with kitchen twine to keep the chicken compact while cooking.
Prepare the Vegetables: Place the sliced onions and chopped carrots at the bottom of the slow cooker.
Assemble the Slow Cooker: Position the chicken on top of the vegetables in the slow cooker. Spread the softened butter across the top for extra moisture.
Cook the Chicken: Cover the slow cooker and set it to cook on low for 6-8 hours or on high for 4-5 hours. Avoid opening the slow cooker during cooking to maintain a consistent temperature.
Remove: Once the chicken is cooked, carefully remove it from the slow cooker. It should be tender and easily pull away from the bone.
Rest: Let the chicken rest for 5-10 minutes before carving. Serve it alongside the cooked onions and carrots.
Garnish: Optionally, you can drizzle the chicken with the juices left in the slow cooker for extra flavor.