Peel and dice 10 ounces Yukon Gold potatoes. Place in medium saucepan and add enough cold water to cover by about 1 inch. Bring to a boil over medium-high heat. Simmer until very tender and a fork easily pierces the flesh, 10 to 15 minutes. Meanwhile, finely chop 1/4 bunch fresh chives until you have 1 tablespoon. Finely grate the zest of 1 medium lemon until you have 1 teaspoon; juice the lemon until you have 2 tablespoons. Place 6 peeled garlic cloves and 1 teaspoon kosher salt in a mortar and pestle and smash until smooth. (Alternatively, finely mince the garlic, sprinkle with salt, then run the side of the blade of a large knife over the garlic until a paste is formed.) Transfer to a medium bowl.
When the potatoes are ready, drain and rinse under cold water to remove the excess starch. Process the potatoes through a food mill or ricer, or mash with a potato masher (which won't be as smooth).
Whisk 2 large egg yolks into the garlic paste one at a time, and whisk until creamy and pale yellow. Add the lemon juice and zest and whisk to combine. While whisking constantly, pour in 1 cup olive oil in a thin, steady stream until the mixture is thick and emulsified, about 2 minutes. Add the potatoes and stir to combine.
Transfer the skordalia to a serving bowl. Drizzle a little olive oil on top and garnish with the chives.
