The vegetables: pretty much anything that grows in your garden, right up to small fruit trees (for example, some people in warmer climates grow paw paw). Anything that's green and leafy gets the biggest advantage due to the abundance of Nitrate. You don't have to grow vegetables - flowers do fantastically as well.
The fish: Canberra's climate is best suited to trout. You can grow a Trout from fingerling to plate size in 9 months, so if you get them in March when the weather starts to cool off you can be eating them by christmas. Other popular species are silver perch, freshwater mussels, yabbies, eel tailed cat fish, goldern perch, murray cod and other native fish.