Whisk the salt into a gallon of water in a large pot until fully dissolved and no salt sinks to the bottom of the pot. Add the potatoes to the pot, bring to a boil over high heat, and then reduce to a simmer and cook until the potatoes are fork-tender and about a quarter of the water has evaporated, about 25-35 minutes.
Drain the potatoes in a colander and allow to sit while salt crust develops. Meanwhile, melt the butter in a microwave-safe bowl. Drizzle the melted butter over the potatoes or serve on the side for dipping. Sprinkle the potatoes with chopped herbs and serve immediately.