Description

Smooth mashed potato, melted cheese, slow-cooked soft alliums, and woody herbs-in terms of eligibility for a book called Comfort, this dish almost feels like cheating.


Ingredients

  • 4 large leeks, cut into ½-inch/1cm rounds (5⅓ cups/560g)
  • 4-5 shallots, peeled and quartered (10½ oz/300g)
  • 1 head of garlic, cloves peeled and lightly smashed
  • ¼ cup/60ml olive oil
  • 2-3 bunches of green onions, cut crosswise into quarters (9 oz/250g)
  • 1½ tbsp thyme leaves, chopped
  • 5 tbsp/75g unsalted butter
  • 1½ cups/360ml heavy cream
  • 7 tbsp/100ml milk
  • 3 rosemary sprigs
  • 2-3 thyme sprigs
  • 2½ lb/1.2kg russet (or other floury) potatoes, peeled and cut into roughly 1¼-inch/3cm chunks
  • 1½ tbsp Dijon mustard
  • 9 oz/250g Comte, coarsely grated (2½ cups)
  • 4½ oz/120g cheddar, coarsely grated (1 cup)
  • ¼ oz/5g chives, finely chopped, to garnish
  • salt and black pepper
  • 1 tbsp unsalted butter, melted
  • 1 cup/20g panko breadcrumbs

Method

  1. Preheat the oven to 450°F.
  2. Place the leeks, shallots, and half the garlic cloves on a parchment-lined baking sheet. Pour 3 tablespoons of the oil over the top, and add ¾ teaspoon of salt and some pepper. Stir well, then roast for 20 minutes.
  3. Add the green onions, chopped thyme, the remaining 1 tablespoon of oil, and another good grind of pepper. Stir together and roast for 15 minutes, until everything is deeply golden. Set aside.
  4. Make the crumb topping by mixing together the melted butter and panko breadcrumbs in a small bowl. Set aside.
  5. Crush the remaining garlic cloves to a paste and put them into a small saucepan, for which you have a lid, along with the butter, cream, milk, and the rosemary and thyme sprigs. Place on medium heat and, just before it comes to a simmer, switch off the heat, cover, and set aside to infuse.
  6. Put the potatoes into a large saucepan, for which you have a lid, and fill with just enough water to cover them. Place on medium-high heat, add 2 teaspoons of salt, and bring to a boil. Cook for 20-25 minutes, partially covered, until tender. Drain, return the potatoes to the pan, and mash well until no lumps remain.
  7. Return the garlic-infused cream to the heat to warm through-the herbs can be discarded. Place the potatoes on low heat and, a third at a time, add the cream to the potatoes. Beat with a wooden spoon, until the cream is fully absorbed, and then add the mustard. Add the cheese, a handful at a time, and beat quite thoroughly until the potatoes become shiny, silky, and elastic. Add ¼ teaspoon of salt and a good grind of pepper, and spoon the potatoes into a large ovenproof dish.