The text on traditions about the preservation of fish - Gravlax, surströmming - is by renowned Swedish professor Jan-Öjvind Swahn, Lund Sweden. Recipes and photos are reprinted with permission from ICA Bokförlag’s book, From the Swedish Kitchen: Fifty Classic Recipes from Sweden, or, in Swedish, Det Svenska köket.

Gravlax with a mustard sauce
(serves 10)
2 lb of salmon, midsection of one filet, fresh and of the highest quality
2 teaspoons oil
4 tablespoons sugar
2 tablespoons salt
1 teaspoon crushed white pepper corns
1 big chopped bundle of dill

Wipe the salmon clean. Ask the store to filet the salmon or pull the bones out yourself with a plier, remove all surface fat and bones. Leave the skin. Moisten the salmon with oil, mix the spices with the dill and rub the mix onto the salmon.
Put a good quantity of dill in an appropriate bowl (some actually use a plastic bag instead), place the salmon skin up on top of the dill and put more dill on top. Cover with a chopping board or similar light weight and leave the salmon in the refrigerator for 12 – 24 hours. Flip the salmon a couple of times. Just under 24 hours should be right, leaving the salmon for too long will make it hard and dry.
Scrape off the herbs and cut the salmon in thin slices or 2.5 inch thick straight cuts, free from skin. The skin (which has to be peeled) may be cut into half inch wide strips, dipped in oil, fried and served with the salmon.

Mustard Sauce ‘Gravlax Sauce’

1 tablespoon mild Swedish style mustard
1 teaspoon dark French mustard
1/2 tablespoon honey
1 tablespoon red vinegar
salt and pepper
lots of chopped dill

Mix mustards with honey and vinegar, spice with salt and pepper. Mix with the oil under constant mixing with a fork. When the sauce is mixed to about the same consistency as mayonnaise, mix in the dill and add salt and pepper to taste.

Combine gravlax with dill potatoes or a potato salad, Potato salad with herbs

And one for the brave:

1 can of surströmming (no substitutes available)
Flatbread
Kidney potatoes
Chopped onion
Butter