Rainbow Trout is the sustainable, low mercury fish labelled a “best choice” by the EPA and FDA. This colourful patterned fish is a member of the salmon family and is one of the healthiest dishes you can include in your diet. … It also has one of the richest omega-3s content of all fish. Rainbow trout meat is mild, with a delicate, nut-like flavour. The flesh is tender, flaky and soft.