Majorstuen Sushi has a great selection of sushi, at very nice prices! They mainly offer take-away, and the food is usually done in about 15 min. This is my favourite spot for picking up sushi on the go, whenever I'm in the area. If you come on a nice day, make your way by foot or by the metro to Majorstuen, pick up your favourite sushi here, and walk five minutes to Frognerparken and enjoy a little picnic.