Glasmästarsill
Glassblower's Herring

From Time/Life's Foods of the World - The Cooking of Scandinavia, 1968:

Pickling liquid:

3/4 cup white vinegar
1/2 cup water
1/2 cup sugar

Other ingredients:

2 salted herring, 1 to 1 1/2 pounds each, cleaned and scraped, and soaked in cold water for 12 hours, or substitute 4 canned matjes herring fillets
1 half-inch piece fresh horse-radish root, scraped and thinly sliced, or substitute 2 tbsp prepared horse-radish, drained and squeezed dry in a kitchen towel
1 medium carrot, peeled and thinly sliced (3/4 cup)
2 small onions, preferably red, peeled and thinly sliced (3/4 cup)
1 quarter-inch piece of ginger root, thinly sliced (optional)
2 teaspoons whole allspice
2 teaspoons whole yellow mustard seeds
2 large or 3 small bay leaves

Bring the vinegar, water and sugar to a boil in a 1- to 1 1/2-quart enamled or stainless-steel saucepan, stirring constantly until the sugar completely dissolves. Then remove the pan from the heat and let the pickling liquid cool to room temperature.

Meanwhile, wash the herring in cold running water and cut them into 1-inch-thick pieces. arrange a thin layer of onions in a 1-quart glass jar (a Mason jar, if possible) equipped with a tightly fitting cover. Top with a few slices of herring, carrots, ginger root and horse-radish, and scatter with allspice, mustard seeds and a bay leaf. Repeat until all of the ingrediets have been used, making three or four layers.

Pour the cool pickling liquid into the jar; it should just cover the contents. Close the jar securely and refrigerate ot for 2 or 3 days. Serve as an appetizer, or as part of a smörgåsbord.