Neapolitan pizza$$frogner
Villa Paradiso's Frogner outpost by Solli plass bakes Neapolitan pies with hand-picked Italian ingredients, in an art-nouveau dining room that is the dressed-up sibling of the original Grünerløkka pizzeria.
Signature: Margherita, Bufala
Order: Bufala with buffalo mozzarella, basil and San Marzano tomato.
Tip: Family-friendly room; the kitchen runs through the afternoon, so it is a reliable late-lunch stop on Frogner's museum walk.
Traditional Norwegian$$$holmenkollen
Frognerseteren at the top of Holmenkollen is the 1891 dragon-style mountain restaurant 30 minutes by metro from central Oslo, with traditional Norwegian dishes, romegrot and the apple cake locals ride Line 1 for.
Signature: Frognerseteren apple cake, Romegrot sour-cream porridge
Order: Apple cake at Kafé Seterstua; reindeer at Finstua upstairs.
Tip: Sunset window seats on the Oslo-facing wall fill first; the casual cafe downstairs is walk-in only.
Traditional Norwegian$$gronland
Asylet on Grønland in Oslo's old town is the wood-panelled 1730 merchant-yard timber building, one of the city's oldest, serving kjottkaker, lutefisk and reindeer in a year-round Christmas-cosy room.
Signature: Kjottkaker with mash, Reindeer stew
Order: Kjottkaker with brown sauce and lingonberry; reindeer stew in winter.
Tip: The courtyard runs late spring through summer; the back-bar fireplace is the winter seat.
Traditional Norwegian$$$kvadraturen
Engebret Café at Bankplassen 1 is Oslo's oldest continuously operating restaurant, founded 1857 by Engebret Christoffersen, in a 1760s listed building where Ibsen, Bjørnson, Grieg and Munch all had regular tables.
Signature: Lutefisk in season, Reindeer fillet
Order: Lutefisk in the November-December season; reindeer fillet year-round.
Tip: Open from 17:00 weekdays; the lutefisk season runs through Advent and books out by mid-November.
Traditional Norwegian$$$sentrum
Stortorvets Gjæstgiveri at Grensen 1 occupies a 1699 listed building one corner from Stortorvet square, with a la carte Norwegian classics, a courtyard for summer and the most-booked lutefisk room from October to Christmas.
Signature: Lutefisk in winter, Smorbrod platter
Order: Lutefisk plate October to Christmas; smorbrod at the cafe in summer.
Tip: The courtyard runs May to September; lutefisk season books out by November.
Modern European$$$sentrum
Theatercaféen on Stortingsgata is the 1900 art-nouveau brasserie opposite Nationaltheatret, in the same family for four generations, with a portrait gallery of its regulars on the walls.
Signature: Norwegian smorbrod, Plateau of seasonal fish
Order: Smorbrod at lunch with a glass of Norwegian aquavit.
Tip: Lunch service has the easiest seats; the room books out at dinner around theatre programming.