Look for the orange "Sushi Bar" sign located downstairs inside David Jones itself (not in the food court).
You will find a large glass case full of quality take away packs of sushi made daily. Packs range from medium to large in size and sell for about $8-14 per pack.
There are also a number of single sushi rolls for $2.95 each such as Tempura Prawn, California Roll, Teriyaki Salmon & Avocado, Salmon & Avocado, Cooked Tuna & Avocado, Chicken Katsu, and Teriyaki Chicken & Avocado.
The take away sushi rolls come in a clear plastic wrapper for easy transport. A small plastic fish containing soy sauce is also enclosed. Here is the Teriyaki Chicken & Avocado roll ($2.95).
Instead of the nori (seaweed) wrapping around the outside like most sushi rolls, the sushi rolls from David Jones have the rice on the outside and the nori on the inside. This is sometimes referred to as an "inside out" sushi roll. The result of this construction is a slightly different flavour and experience which I really enjoy. Protip: Do not remove the sushi from its wrapper but simply peel the wrapper open. The clear plastic will easily split down the seams on the sides. This method is demonstrated below with the Chicken Katsu roll ($2.95).
There's also an eat in menu available with a variety of made to order plates which look quite tasty, but the take away options seem to be the most popular. With so many places around Adelaide to buy sushi, it can be difficult to decide where to go. David Jones Sushi Bar is at the top of my list of tried and tested sushi favourites in the city.
Update 30 April 2014: Due to the closure of Food Glorious Food, David Jones Sushi has relocated to Cafe Delores in Renaissance Arcade!