Prepare the thickener: Peel the yam cut into chunks then boil until soft then pound; you can use a blender/food processor/food processor/mortar and pestle then set aside. Make sure your pounded yam is not too thick so it will dissolve easily. I usually store my yam in the freezer in case if you're wondering why the yam looks dry...lol
Place the catfish in a big pot and cover with water depending on big your pot starts with about 3 cups then add more if you need to afterward. Season with seasoning powder/cube, chopped onion, salt and cook for about 10 minutes (depending on how big is your fish) until it’s almost done.
Dry mill your spices (ehuru, uda, uziza, rodo), Sieve the spices after grinding to remove any chunk spice.
Chop the iru/locust beans (or pound it), then add to the fish with the spices and pepper.
Continue the cooking then throw in the thickener; pounded yam paste then shake so you don’t break the fish apart. Season with seasoning powder and salt, keep it in mind that you’ve added some seasoning to the fish before. Allow the thickener dissolves and the fish is fully cooked.