1 Peel onion, halve and cut into very thin slices. Rinse marjoram, shake dry and pluck leaves.
2 In a pan, heat butter until foamy. Cook onion until translucent, stirring occasionally, about 2 minutes.
3 Meanwhile, rinse apple, wipe dry, quarter and core. Cut apple quarters into thin slices.
4 Add apple slices and marjoram to the onion and cook until the apple slices are lightly browned, 2-3 minutes.
5 Meanwhile, rinse herring and pat dry with paper towels.
6 Season the apple-onion mixture with a little pepper and divide among plates. Top with herring and ligonberries and serve with the rolls.