Grab russets that are roughly the same size. Yes, this means digging through the bin at the store while people give you looks. Worth it. Cover them with cold water and salt it like you mean it, a full quarter cup of kosher salt. Sounds like way too much. It's not. That's the only shot you get at seasoning the potato from the inside instead of just the outside.

High heat to get it going, then drop it down to a steady medium-low simmer. Mine took about 40 minutes, but don't trust that number poke it with a skewer instead. You're looking for tender all the way through, not falling apart, not still firm in the center.

This is the step everyone rushes and it's the one that matters most. Hot potatoes plus mayo equals a greasy, broken mess. Fridge-cold potatoes get a weird texture. Room temp is where you want to be I just set mine near an open window and go do something else for a while.

Mayo, apple cider vinegar, Dijon, salt, pepper, a pinch of cayenne. Real mayo, not the fat-free stuff that's a different food entirely. If it's ready before the potatoes are cool, just stick it in the fridge. Do not, under any circumstances, put this on warm potatoes.

The skins should come off with barely any effort once they're cooled a light scrape does it. You might see some discoloration right under the skin; that's normal, purely cosmetic, ignore it. Cut the pieces about three times bigger than you actually want in the finished salad. They break down as you mix, so small now means much later.

Potatoes into a big bowl, plus onion if you're using it, celery, parsley, sliced hard-boiled egg. Give everything a stir before the dressing goes in I'm honestly not sure it makes a real difference, but it's how I've always done it. Then in goes the dressing.

I know. I know you want to. Don't you genuinely can't judge this until it's had time in the fridge. A couple hours minimum, longer if you can wait that long.

It'll look a little sad and separated at first. Totally fine, just stir. Taste for salt (it almost always needs more) and check if it looks dry (also almost always needs a bit more mayo). Adjust, stir, taste again.