1Peel and dice potatoes into even-sized chunks (roughly 1-1.5”). Add to a large pot and pour in enough stock to comfortably cover them. Stir in 1 tsp salt then bring to a boil. Cook until knife tender (approx 12-15 mins). Drain.
2Leave potatoes to steam for 1 minute. Add butter and milk to the pot and stir to melt the butter.
3Add potatoes to the pot and mash until relatively smooth. Add the Boursin and continue mashing until smooth, then season with salt and pepper.
4Add to a serving dish and use a spoon to swirl the top. Drizzle over the melted butter and sprinkle with chives.