1.Dry-fry nuts in large frying pan over low heat, shaking pan constantly until fragrant. Remove from heat. When cool enough to handle, chop nuts coarsely.
2.Melt butter in same pan. Stir nuts and coriander over heat for 1 minute. Add fish and turn halfway through cooking time, until cooked through. Season to taste.
3.Serve fish drizzled with butter mixture.