Place prepared potatoes in a large pot and cover with cold water. Season the water kosher salt. Bring to a boil over high heat, then reduce the heat to medium-low and simmer until the potatoes are tender when pierced easily with a fork, about 15-20 minutes.
Brown 2 tablespoons of butter while the potatoes cook. Set aside.
Drain potatoes and return them to the pot. Add remaining 6 tablespoons butter to the potatoes and mash with a potato masher until mashed but still lumpy. Then add buttermilk, salt, and pepper. Mash until mixture is fully incorporated. If needed, add a bit more buttermilk.
Taste for seasoning and adjust as required. Stir in 3 tablespoons of the chopped fresh chives. Transfer to a serving bowl. Use the back of a spoon to create a swirly, circular channel. Drizzle the browned butter in the channel, and garnished with more chives, if desired. Serve hot.