Ingredients

Equipment Needed

• •Large pot for boiling the potatoes
• •Whisk or wooden spoon
• •Small saucepan for warming milk (optional)

Instructions

1. 1

   Cook the potatoes

   Put the potatoes in a large pot, cover with cold water, and add a generous teaspoon of salt. You start in cold water because potatoes cook from the outside in. Hot water shocks the surface and gives you a crumbling edge around a hard center. Cold water lets the heat travel evenly through. Bring to a gentle boil and cook for fifteen to eighteen minutes, until a knife slides through the largest piece with no resistance at all. Drain and set aside. Don't let them sit in the water once they're done. Waterlogged potatoes dilute the sauce.

   If you're using true new potatoes, the small ones that arrive in June, leave the skins on. They're thin and sweet and belong in the dish. Older potatoes can be peeled if you prefer, but waxy varieties hold their shape either way.
2. 2

   Make the roux

   Melt the butter in the same pot over medium-low heat. When it foams, add the flour all at once and stir with a wooden spoon or a small whisk. Cook the paste for about two minutes, stirring constantly. You want the raw flour taste to disappear, but the roux should stay pale, not golden. This isn't a brown sauce. The colour of the finished stuvning should be cream-white and clean.

   If the roux starts to colour, pull the pot off the heat for a moment and keep stirring. You can always slow things down. You can't undo a browned roux in a white sauce.
3. 3

   Build the sauce

   Add the warm milk in a slow, steady stream, whisking constantly as you pour. Go slowly with the first third. This is where lumps form, when the milk hits the roux too fast and the flour seizes into clumps. Once the first third is incorporated and smooth, you can pour more freely. Add the cream and keep whisking. Let the sauce come to a gentle simmer and cook for five minutes, stirring often. It should thicken to the consistency of double cream, coating the back of a spoon in a smooth, even layer. Season with salt, white pepper, and a small grating of nutmeg.

   Warm the milk before adding it. Cold milk hitting a hot roux is what causes lumps. If you forgot to warm it, pour even more slowly and whisk harder. If lumps do form, push the sauce through a fine sieve. No one will know.
4. 4

   Add the potatoes

   Slide the drained potatoes back into the sauce and fold them through gently with a spatula or large spoon. Don't stir aggressively. You want the potatoes to hold their shape inside the sauce, not break apart into mash. Let everything simmer together for three to four minutes so the potatoes absorb some of the sauce and the flavours marry. The sauce will thicken slightly around the potatoes. That's right. It should cling to them, not pool around them like soup.

5. 5

   Finish with dill and parsley

   Take the pot off the heat. Stir in the chopped dill and parsley now, not during cooking. Heat destroys fresh dill in seconds. It goes grey, loses its fragrance, and tastes of nothing. Added at the end, off the heat, the dill stays green and bright and floods the sauce with that grassy, anise-edged flavour that is the whole point of the dish. Taste the sauce one last time. Adjust the salt. You'll know when it's right.

   Be generous with the dill. This dish is named for it. The sauce should be visibly green-flecked, fragrant enough that you can smell it from across the kitchen. If you're wondering whether you've added enough, add a little more.
6. 6

   Serve warm

   Spoon the creamed potatoes into a warm serving bowl or straight onto plates alongside the fish. In Denmark this goes next to stegt rodspatte, pan-fried plaice, or beside poached torsk, cod, with a wedge of lemon and nothing else. The potatoes are the soft, creamy, herb-laced anchor that lets the fish be simple. Serve immediately while the dill is still vivid and the sauce is loose and silky.

Chef Tips

• •Use waxy potatoes, not floury ones. Floury potatoes break apart in the sauce and turn the whole thing into something closer to mash. Waxy potatoes hold their shape and give you that contrast of firm, tender potato inside a smooth sauce. New potatoes in season are best of all.
• •White pepper, not black. Black pepper leaves dark specks in the white sauce and tastes sharper than you want here. White pepper is quieter, warmer, and disappears into the sauce visually while doing its work. This is standard in Danish white sauces.
• •If you have leftover sauce and potatoes, they keep overnight in the fridge. Reheat gently with a splash of milk to loosen the sauce, which thickens as it cools. Stir in a little fresh dill again before serving. Yesterday's dill has faded.
• •A squeeze of lemon juice stirred in at the very end, just a few drops, brightens the sauce without making it taste of lemon. It lifts the dill and cuts through the richness. This is a trick from the old summer kitchens on Bornholm.

Advance Preparation

• •The potatoes can be boiled up to a day ahead and kept in the fridge. Bring them to room temperature before folding into the sauce so they don't cool it down.
• •The sauce is best made fresh, but the roux can be prepared in advance and kept covered. When ready, warm the roux gently and add the milk to build the sauce.
• •Do not add the dill until just before serving. There is no way around this. Dill that sits in a warm sauce loses its colour and its point.

Frequently Asked Questions

Nutrition Information

1 serving (about 280g)