Add in the Old Bay seasoning, salt and pepper, and onion slices.
Gently mix all the ingredients together.
Turn on the electric skillet, cover and bring liquid to a simmer.
When the liquid is simmering, add in the catfish fillets. Be sure to spoon some of the delicious liquid right over the top of the fillets to really get them coated with that flavor.
Cover, reduce heat to 145 and poach for 9 minutes.