Wash and cut the potatoes into bite-size pieces (leave skins on for texture).

Clean shiitake mushrooms with a brush or damp towel (avoid soaking).

Clean and chop the leek.

Heat olive oil in a medium skillet over medium heat.

Add leeks and sauté until soft (~2 minutes). Watch them closely to avoid burning them.

Add shiitake, season with salt & pepper, and cook until golden and tender (~5 minutes). Toward the end, add minced garlic.

Deglaze with a splash of vinegar or white wine, stirring to release any browned bits.

Boil in salted water until fork tender (about 12-15 minutes).

Drain the cooked potatoes and set them aside.

Bring water to a boil, then gently lower the eggs.

Cook for 6.5–7 minutes for jammy yolks.

Transfer immediately to an ice bath, then peel and set aside.

In a small bowl, whisk mayonnaise with Dijon mustard until smooth.

Slowly add lemon juice and one teaspoon of white wine (optionally), letting the mixture lighten and thin slightly. If using white wine, let it sit for a minute to allow the flavors to meld.

Stir in capers, a small pinch of nutmeg, salt, and freshly ground black pepper. Adjust seasoning to taste.

If the dressing feels too thick, add one teaspoon of warm water or a drizzle of olive oil to loosen it up slightly.

Set aside for at least 5 minutes.

Toss the drained potatoes with the dressing and let them absorb the flavors. Mix in fresh dill.

Fold in the sautéed shiitake and leeks to the potato mixture.

Halve the soft-boiled eggs and place on top.