Begin by gathering all necessary ingredients. Fill a turkey fryer or a sizable stockpot with sufficient oil to submerge the turkey, ensuring there is enough space to prevent any overflow. Heat the oil to 400°F (200°C), and prepare a large platter lined with food-safe paper bags.

Rinse the turkey thoroughly and dry it completely using paper towels. Generously rub the Creole seasoning inside the cavity as well as over the entire surface of the turkey. Ensure the neck opening is at least 2 inches wide to allow oil to flow freely into the cavity.

Once the oil reaches the desired temperature, switch off the heat source. Place the whole onion into the drain basket, followed by the turkey, positioning it neck-end first. Gently lower the basket into the fryer until the turkey is entirely submerged in the oil. Reactivate the heat source and maintain the oil temperature at 350°F (175°C). Cook the turkey until it is no longer pink at the bone, and the juices run clear—approximately 45 minutes, or 3 ½ minutes per pound.

After cooking, carefully lift the basket from the fryer to drain the turkey. An instant-read thermometer inserted into the thickest part of the thigh, close to the bone, should register at least 165°F (74°C) but no higher than 180°F (80°C). Transfer the turkey to the prepared platter and allow it to drain for 10 to 15 minutes before serving.

Serve warm and savor the deliciousness!