Start by thawing your shrimp overnight in the fridge. Alternatively, thaw them in a strainer in running cold water and pat dry with a paper towel.
Peel and chop your red onion into small cubes. Grate the skin of your lemon. A microplane is a handy tool for this.
Squeeze half of lemon and add the juice into the bowl. Add your chopped dill.
Add the mayo and sour cream. Season with salt and pepper. Mix well.
Gently fold in the thawed shrimp, ensuring they are well coated with the creamy mixture. Cover the bowl and refrigerate the Skagenröra for at least 30 minutes. Chilling allows the flavors to meld and enhances the overall taste.
Serve on top of toast, on top of rye bread, as a filling in baked oven potato or sweet potatoes. It even makes nice flatbread roll-ups or deviled eggs.
Notes
Red onion can be replaced with shallot or spring onion. A pinch of grated horseradish gives a nice variation. Add more lemony taste by serving your guests with lemon wedges. Do not thaw your shrimp with boiling water since you end up with rubbery ones. Stores in the fridge for a day.