Huge Shepherd's Pie

Ingredients

• 2.5 lbYukon gold potatoes, peeled and cut into 2-inch chunks
• as needed, plus 1.5 tspkosher salt
• 6 tbsp, dividedunsalted butter
• 1/2 cup, warmedheavy cream
• 1large egg yolk(the secret weapon — gives the mash structure)
• 1.5 lbground lamb(lamb. LAMB. If you use beef you've made cottage pie, which is a different recipe)
• 1 tbspolive oil
• 1 mediumyellow onion, finely diced
• 2 mediumcarrots, finely diced
• 3 clovesgarlic, minced
• 2 tbsptomato paste
• 2 tbspall-purpose flour
• 1/2 cupdry red wine
• 1.5 cupsbeef stock, low-sodium
• 2 tbspWorcestershire sauce
• 1 tbspfresh thyme leaves
• 1 tspfresh rosemary, minced
• 1 cupfrozen peas
• 1 tspblack pepper
• 1/4 cupgrated parmesan (optional, for topping)

Steps

1. 1

   Place the potato chunks in a large pot, cover with cold water by 2 inches, add a generous pinch of salt. Bring to a boil, then reduce to a strong simmer and cook until fork-tender, 15-18 minutes.

2. 2

   Drain the potatoes thoroughly and return them to the warm empty pot. Let them sit 1-2 minutes to dry out — this is critical for fluffy mash.

3. 3

   Mash the potatoes with 4 tbsp of the butter and the warm cream until smooth. Stir in 1 tsp salt and let cool 5 minutes, then whisk in the egg yolk. Taste and adjust salt. Set aside.

4. 4

   While the potatoes cook, heat the olive oil in a large oven-safe skillet (12-inch) over medium-high. Add the ground lamb and cook, breaking it up, until browned and the fat has rendered, 6-8 minutes. Drain off most of the fat, leaving about 1 tbsp in the pan.

5. 5

   Add the onion and carrots. Cook 6-7 minutes until softened.

6. 6

   Add the garlic and tomato paste. Stir constantly for 2 minutes until the paste darkens.

7. 7

   Sprinkle the flour over the meat and vegetables, stir for 1 minute.

8. 8

   Pour in the red wine, scraping up the fond. Simmer 2 minutes until reduced by half.

9. 9

   Add the beef stock, Worcestershire, thyme, rosemary, remaining 1/2 tsp salt, and pepper. Simmer 10 minutes until the gravy has thickened and clings to the meat.

10. 10

    Stir in the peas. Taste and adjust seasoning. Remove from heat.

11. 11

    Preheat the broiler. Position a rack about 8 inches from the broiler element.

12. 12

    If using a separate baking dish, transfer the lamb filling to a 9x13 dish. Otherwise leave it in the oven-safe skillet.

13. 13

    Dollop the mashed potatoes over the filling and spread evenly with a spatula, sealing to the edges of the pan.

14. 14

    Drag the tines of a fork across the top of the potatoes in a crosshatch pattern to create peaks and ridges — peaks crisp up under the broiler.

15. 15

    Melt the remaining 2 tbsp butter and brush over the top of the potatoes. Sprinkle with parmesan if using.

16. 16

    Broil 5-8 minutes, watching closely, until the peaks are deeply golden and the filling is bubbling at the edges.

17. 17

    Let rest 5 minutes before serving.