Prep the potatoes: Rinse and scrub the potatoes. If they’re larger than bite-size, cut them into halves or quarters so they cook evenly.
Boil until tender: Place potatoes in a pot, cover with cold water by about an inch, and add 1 teaspoon kosher salt.
Bring to a gentle boil and cook until a knife slides in easily, about 12–15 minutes for small pieces.
Drain and steam-dry: Drain the potatoes well, then return them to the warm pot. Let them sit, uncovered, for 2–3 minutes to steam off excess moisture. This helps them absorb the dressing.
Make the vinaigrette: In a small bowl, whisk together olive oil, lemon zest, lemon juice, Dijon, garlic, and honey.
Season with a big pinch of salt and several grinds of pepper. Taste and adjust acidity or salt as needed.
Dress while warm: Transfer warm potatoes to a large bowl. Pour about two-thirds of the vinaigrette over them and toss gently with a spatula or wooden spoon so they don’t break apart.
Add herbs and extras: Fold in parsley, dill, chives, and scallions.
If using capers and celery, add them now. Toss again, then taste and add more dressing, salt, and pepper as needed.
Rest for flavor: Let the salad sit for 10–15 minutes at room temperature so the potatoes soak up the vinaigrette. Right before serving, toss once more and add a squeeze of lemon if you like extra brightness.
Serve warm or chilled: It’s delicious slightly warm, room temperature, or after chilling for an hour.
If serving later, add a splash of olive oil and lemon to refresh.