A quick hello and the backstory

I make this Steakhouse Potato Salad whenever the grill is hot and the porch chairs are a little squeaky. It started as a what on earth do I do with these last two potatoes situation and turned into the salad my brother asks for by name. One time I brought a bowl to a neighbor barbecue and someone borrowed my mustard, brought it back with three compliments and a story about their uncle in Ohio. Long story short, this salad makes friends.

Also, very random, but I once melted a spatula trying to multitask between the potatoes and a pan of onions. It smelled like a science fair. We still ate the salad. Nobody noticed, which I choose to take as a compliment to the dressing.

Why you might love this, like I do

I make this when the steak is resting and I want something cool and creamy with a bit of bite. It is the steady friend to all that sizzle.
My family goes a bit bonkers for the tangy dressing and the chives on top. The crunch from celery seals the deal, every single time.
When I am feeling fancy, I add a tiny puff of horseradish and it suddenly tastes like the side dish at a proper steakhouse. Or at least the one down the road with the squeaky leather booths.
Confession, I used to overcook the potatoes and ended up with mush. Now I let them steam dry and actually, I find it works better if you cut them after cooking. Less crumble, more bite. Learned the hard way.

What you will need, plus a few honest swaps

900 g waxy potatoes like Yukon Golds or small red potatoes, scrubbed; skin on if you like texture
2 tablespoons apple cider vinegar, divided
1 teaspoon kosher salt, for the water, plus more to taste
1/2 cup mayonnaise about 120 g; my grandmother swore by Hellmanns, but honestly any good mayo works
1/3 cup sour cream about 80 g; Greek yogurt works in a pinch, a bit less rich
1 tablespoon Dijon mustard or whole grain mustard if you want little pops
1 to 2 teaspoons prepared horseradish optional but so good
1 small garlic clove finely grated, or 1/4 teaspoon garlic powder if you are not into raw garlic
2 celery stalks, finely chopped
1/4 small red onion, very thinly sliced
1 dill pickle, finely chopped, plus a spoon of the brine, optional
A handful of fresh chives, snipped
2 tablespoons finely chopped parsley or dill, your call
Fresh cracked black pepper, plenty
Optional but fun: 2 slices crispy bacon, crumbled; for a veggie vibe use a pinch of smoked paprika instead
Optional seasoning twist: a pinch of your favorite steak seasoning, I tend to think it makes the flavors echo nicely

Quick read you might enjoy while the water heats up, the detailed potato boiling basics on Serious Eats are solid. If you are mayo curious, I like this simple explainer on Japanese mayonnaise for a different flavor vibe.

How I actually make it, step by step but not fussy

Scrub the potatoes. Leave them whole if they are small or halve if they are chunky. Drop into a pot of cold water with 1 teaspoon kosher salt. Bring to a gentle boil and cook until a knife slips in with just a whisper of resistance. About 12 to 18 minutes depending on size. Do not rush this. I once did and regretted it because the centers were firm while the outsides were falling apart.
Drain and let the potatoes sit in the colander for 2 minutes. Then spread on a sheet pan to steam dry. While they are hot, sprinkle over 1 tablespoon of the vinegar. Let them cool until you can handle them without doing the hot potato dance.
Meanwhile, in a big bowl whisk together mayo, sour cream, mustard, horseradish, garlic, remaining 1 tablespoon vinegar, a pinch of salt, lots of black pepper, and the pickle bits if using. Taste. This is where I usually sneak a taste, maybe two. If it is too thick, loosen with a splash of water or a bit of pickle brine.
Soften the onion slices by soaking them in cold water for 5 to 10 minutes. Drain and pat dry. This knocks back the sharpness, learned that trick form my aunt.
Cut the cooled potatoes into bite size chunks. Do not worry if some pieces look a bit rough at this stage, it always does and then it comes together.
Add potatoes, celery, onion, and herbs to the bowl. Gently fold with a spatula until everything is coated. Go slow. You want the dressing to hug each piece, not mash it.
Taste again for salt, pepper, and tang. If you want more zip, a squeeze of lemon is lovely. Or a pinch more mustard.
Chill for at least 30 minutes so the flavors can hang out and become friends. Or do what I do when people are hungry, serve it slightly warm and pretend it was a plan all along.
Right before serving, shower with extra chives and the bacon crumbs if you are using them.

Little notes from my messy notebook

Cut after cooking helps the potatoes keep their shape. When I cut before, too many edges went fuzzy.
A tiny bit of vinegar on hot potatoes changes everything. If you like to nerd out, The Food Lab explains why. Here is the classic deep dive on potato salad science.
On second thought, if you hate raw onion, skip it and add more chives. It is your bowl.
If the dressing tastes flat, nine times out of ten it needs salt. The tenth time it needs acid.

Variations I have tried, for better or worse

Blue cheese crumble with extra chive and a crack of pepper. Wildly good with steak, but go light so it does not bully the potatoes.
Roasted garlic instead of raw. Sweeter, cozier. I liked it more the next day.
Smoked paprika and chopped roasted red peppers for a smoky picnic vibe.
Too much horseradish experiment. Everyone cried a little and we laughed a lot. Dial it back to 1 teaspoon unless you enjoy dramatic salads.
Warm version with a splash of beef drippings stirred into the dressing. Tastes like a pub in the best way. Not exactly light, but hey.

Gear I used, plus workarounds

Large pot for boiling. I call it essential, although honestly a deep skillet will do in a pinch if that is what you have.
Colander. No colander? Use a slotted spoon and let the potatoes sit on a clean towel to drain.
Sheet pan to steam dry the potatoes. A big plate works fine.
Mixing bowl and a rubber spatula. Or just stir gently right in the pot if you are short on dishes.
Sharp knife and cutting board. If your knife is dull, I like to score the potatoes with a butter knife and break them with a spoon. Not elegant, works.

How to store it without losing the magic

Keep the salad in an airtight container in the fridge for up to 4 days. I think it tastes better the next day after the potatoes soak up the dressing. If it firms up, stir in a spoon of sour cream or a splash of vinegar to loosen. Though honestly, in my house it never lasts more than a day.

How I like to serve it

With grilled ribeye or a pile of portobello mushrooms. Sometimes I scoop it into crisp lettuce cups with extra chives and a squeeze of lemon. Family tradition here, we pass the pepper grinder around the table and everyone adds two twists for good luck. Silly, but we do it anyway.

Pro tips I learned the hard way

I once tried rushing the cool down step and regretted it because the dressing slid off and pooled at the bottom. Let the potatoes steam dry first, then cool until just warm.
Salting the water matters. I forgot once and the salad tasted fine on the outside, bland inside.
Cut consistent size. When I went all willy nilly, some pieces turned to mush while others were underdone.
Do not over stir. It is potato salad, not mashed potatoes. Gentle folding is your friend.

FAQ I actually get asked

Can I make this without mayo?
Yep. Go half Greek yogurt and half olive oil. It will be lighter and a touch tangier. Add an extra pinch of mustard to help it emulsify.

Do I need to peel the potatoes?
Nope. I rarely do. Skins add texture and color. If you prefer silky smooth, peel after cooking while they are still warm. Careful, they are toasty.

What if I only have russet potatoes?
They work, just be extra gentle and maybe cube them a bit larger. They are more starchy and can break if you stir with gusto.

How do I tone down raw onion flavor?
Soak slices in cold water for 10 minutes, then pat dry. Or quick pickle them, here is a simple method I like on Bon Appetit.

Can I serve it warm?
Absolutely. Toss the warm potatoes with the dressing and serve right away. It feels very bistro. But chill leftovers promptly.

Is this gluten free?
Yes, generally. Check your mustard and seasoning blends to be sure. Some brands are sneaky with additives.

How do I double it for a crowd?
Use a bigger pot and do the potatoes in two batches so they cook evenly. Dressing scales linearly, but start with a bit less and add to taste.