Bring water to a boil in a large deep pot over high heat.
Once boiling, stir in all of the salt.
Carefully drop the potatoes into the water.
Bring back to a boil and lower the heat to medium. Simmer until the potatoes are tender - 15 to 25 minutes depending on the size of the potatoes. Test tenderness by poking with a fork through the middle. They should be very tender.
Drain the potatoes into a colander and leave to air dry - 5 to 10 minutes.
Transfer the potatoes to a serving dish and drizzle with melted butter.