Any white firm-fleshed fish makes a great alternative and is ideal in this fish curry. Here are a few examples: • tilapia • snapper • barramundi • cod (all types) • mahi-mahi • turbot • halibut • basa • hake • ling • sole • pollock A curry like this is an excellent way to disguise any fish flavor shortfalls so it is a great option for any "fishy" fish, freshwater fish, or a great dish to make for any economical fish use. Salmon and mackerel (Spanish mackerel and the king mackerel) as bluefish options are also great alternatives for this nice dish. Salmon will have to be cut into bigger chunks.