This soup is also known as Lohikeitto.
Wash, clean, and dice all vegetables.
Remove scales from salmon fillet or remove skin entirely, up to you. Dice.
In a pot, melt butter. Add diced leeks and cook on medium-high about 5 minutes until the leeks wilt a bit.
Add water (or stock) and other vegetables. Bring to a boil and cook on medium heat about 10-15 minutes until the potatoes are ready.
Add diced salmon fillet and heavy cream. Cook for additional 5-10 minutes to cook the salmon.
Add salt and pepper to taste at the end. Serve with dill as garnish.