Bring a large pot of salted water to a boil and add the whole, unpeeled potatoes. Boil for 10-15 minutes until they're just tender when pierced with a fork—you want them cooked through but still firm enough to hold their shape. While the potatoes cook, place eggs in a separate pot of cold water, bring to a boil, then remove from heat and let sit covered for 10-12 minutes to hard-boil. This simultaneous cooking saves time and gets both components ready for assembly.

While the potatoes finish cooking, finely dice the celery, pickles, and red onion into uniform small pieces—this ensures even distribution throughout the salad. Chop the fresh dill and set everything aside in separate small bowls. Having everything prepped and ready will make the final assembly quick and seamless.

Drain the cooked potatoes in a colander and return them to the hot pot, covering with a lid for 5 minutes to steam out excess moisture—this prevents a watery salad. Transfer the cooked potatoes to a cutting board and let cool slightly while you shock the hard-boiled eggs in an ice bath for easy peeling. Peel the eggs once cooled, separating the yolks from the whites, and keep them in separate bowls.

Mash the egg yolks in a medium bowl with a fork until smooth, then whisk in the mayonnaise, buttermilk, yellow mustard, pickle juice, celery seed, sea salt, and black pepper. Mix until the dressing is smooth and well-combined. I like to taste the dressing at this point and adjust the seasoning—the pickle juice adds tang but sometimes I add an extra pinch of salt if the potatoes taste bland.

Cut the cooled potatoes into bite-sized chunks (about 3/4-inch pieces) and transfer to a large mixing bowl. Pour the dressing from Step 4 over the warm potatoes and gently fold to combine—the warmth helps the potatoes absorb the flavors. I prefer to dress the potatoes while still slightly warm, as they absorb the flavors much better than cold potatoes.

Chop the reserved egg whites into bite-sized pieces and gently fold them into the dressed potatoes along with the prepared celery, red onion, pickles, and fresh dill from Step 2. Be gentle when mixing to avoid breaking up the potatoes. Refrigerate for at least 2 hours before serving to let the flavors meld together.