1.Preheat oven to moderate.
2.Combine stock, juice and potato in large baking dish; roast, uncovered, in moderate oven 10 minutes.
3.Meanwhile, combine rind and oregano in small bowl. Score fish both sides; press rind mixture into cuts and inside cavity.
4.Place fish in lightly oiled large baking dish; roast, uncovered, in moderate oven about 30 minutes.
5.Meanwhile, add capsicums and garlic to potato mixture; stir to combine. Roast, uncovered, in moderate oven about 30 minutes or until potato is tender. Serve fish with vegetables, drizzled with any pan juices; sprinkle fish with oregano leaves, if desired.
We used a whole barramundi for this recipe, but any whole, firm, white-fleshed large fish can be used.Note