Heat 2 tablespoons of butter in a small sauté pan over medium-high heat. Add 3-4 sage leaves and cook until crisp, about 20 seconds. Transfer to a paper towel-lined plate and sprinkle with salt. Repeat with remaining sage leaves.
Place potatoes in a large pot and cover with 1-inch of cold water. Bring to a boil. Season generously with salt, cover and reduce to a simmer. Cook until fork-tender, about 15 minutes. Meanwhile, gently heat heavy cream and garlic clove in a small saucepan.
Drain potatoes in a colander and return to the warm pot. Let sit a few minutes to dry out. Pass potatoes through a ricer into a large pot, then stir in 1 cup of melted butter. Remove and discard garlic clove from hot cream. Slowly mix cream into potatoes until desired consistency is reached. Season with salt and pepper. Stir in chives.
Transfer potatoes to the serving bowl and use a spoon to create swirls on the surface. Pour remaining ¼ cup melted butter over top. Garnish with fried sage leaves and more minced chives. Serve warm.