Ärtsoppa

Ärtsoppa is a thick Swedish soup of yellow split peas, simmered with pork and served with mustard and pancakes. It is the traditional Swedish pea soup, and eating it on Thursdays, with pancakes to follow, is a long-standing Swedish custom. Finland has a similar Thursday meal of pea soup and pancakes, so the custom is shared between the two countries rather than belonging to only one.

What it really is

Yellow split peas are soaked, then simmered slowly in a pot with pork, often a smoked cut, until the peas break down and the soup thickens. The pork is cooked into the soup rather than served beside it. Onion, bay leaf, marjoram and salt season the pot, so the flavour is savoury and gently herbal rather than sweet.

Ärtsoppa is a meat soup, not a vegetable one. The pork is simmered into the pot with the peas, so the soup is not suitable for vegetarians.

How it's served

• Hot, in a deep bowl, with mustard on the table or served alongside.
• Followed by thin Swedish pancakes, traditionally eaten with jam.
• On Thursdays, which is the traditional day for this meal in Sweden.

How to write it on the menu

• Name the pork and the peas, for example "yellow pea soup with pork", so guests know it is not vegetarian.
• Flag mustard, which is a declarable allergen, and say whether it is served on the side.
• The soup itself has no wheat, egg or milk, but the pancakes do. Flag them on the same line if they come with the soup, and list them as a separate item if they are sold on their own.
• State whether jam is included with the pancakes, since guests often ask.