Adapted from a recipe in Bon Appetit.
Ingredients:
About 2 pounds potatoes Kosher salt 6 tablespoons unsalted butter, divided 2 garlic cloves, thinly sliced 2 cups (packed) finely shredded kale, divided 1 cup milk 1/2 cup heavy cream Freshly ground black pepper
Preparation:
Cover potatoes with salted water in a medium pot. Bring to a boil over medium-high heat, then reduce heat and simmer until a paring knife slides easily through the flesh, 30–40 minutes. Drain, let cool slightly, and peel, if desired.
Meanwhile, melt 4 tablespoons butter in a large saucepan over medium heat. Add garlic and cook, stirring frequently, until garlic is fragrant, about 3 minutes. Add 1 cup kale and cook, stirring constantly, until wilted. Add milk and cream and bring to a simmer.
Add potatoes and remaining 1 cup kale, then coarsely mash with a potato masher. Season with salt and pepper. Transfer colcannon to a large serving bowl. Top with remaining 2 tablespoons butter.