Mashed potatoes receive a much-needed upgrade with this sous vide variation. Rather than boiling potatoes in water, this recipe calls for butter and milk, making the flavor rich and intense. A few cloves of smashed garlic and sprigs of rosemary infuse the potatoes as they're cooking. At about 25% butter, these mashed potatoes are not an everyday kind of recipe, but perfect for special occasions, like Thanksgiving (when calories don’t count)!