Cut the potatoes into halves, this will help the potatoes boil quicker.
Place the washed potatoes into a large pot and cover with water.
Bring to a boil and cook until the potatoes are tender, about 30 - 40 minutes. To check if the potatoes are done, insert a knife or a fork into the center, the potatoes should be soft but not falling apart.
Once done, drain the water, place the pot over low heat and add the butter and half of the warm cream to the pot. Using a wire masher, mash the potatoes until almost smooth, leaving some chunks.
Add the rest of the warm cream little by little, and stir. Season with salt and pepper, taste and adjust.
If you want the potatoes creamier, stir in a little more warm cream.
Transfer to a serving bowl, top with freshly chopped green scallions and a drizzle of olive oil.