In a large saucepan, bring potatoes, 1 teaspoon salt, and water to cover to a boil over high heat. Boil until tender, about 20 minutes. Let cool completely. Slice potatoes into ½-inch-thick slices.
In a large bowl, whisk together buttermilk, mayonnaise, mustard, oil, and remaining 1 teaspoon salt. Gently toss potatoes with buttermilk dressing and dill.
Recipe by Louisiana Cookin' at https://louisianacookin.com/buttermilk-mustard-potato-salad/