Kalf & Hansen is on Mariatorget Square in Södermalm. Visit Stockholm describes its food as Nordic organic fast food, with beef, fish and vegetarian quenelles served with salad and sauces. The restaurant says it uses organic, locally sourced ingredients chosen by season; ingredients that cannot be grown in Sweden are bought organic. It says it works to prevent food waste.

The Mariatorget restaurant is open Monday to Thursday from 11:00 to 20:00, Friday and Saturday from 11:00 to 22:00, and Sunday from 11:00 to 16:00. Kalf & Hansen also has a lunch restaurant at Bolinders plan 3 on Kungsholmen. Its website lists a week 44 lunch menu at 149 SEK (about US$14.0), but that was a past week's menu, not a confirmed price for this week. The website also advertises a Christmas buffet, with meat-and-fish and vegetarian versions, and directs visitors to a booking link. In 2024, Kalf & Hansen received the EU Organic Award for “best organic restaurant/food service.”