Easy Shepherd's Pie

• •
  Potato, Russet, Baked, Flesh Only(680g)
• •
  Unsalted Butter(45g)
• •
  Parmesan Cheese(60g)

  Grated Parmesan — the shelf-stable canister is fine for cooking.

• •
  ½ teaspoon kosher salt
• •
  ¼ teaspoon ground black pepper
• •
  2% Milk(60g)
• •
  Egg Yolk
• •
  Olive oil(15g)

  Regular (not extra-virgin) olive oil for high-heat cooking. EVOO for dressings.

• •
  Yellow Onion
• •
  Garlic
• •
  Tomato Paste(15g)
• •
  90/10 Ground Beef(454g)
• •
  ½ teaspoon kosher salt
• •
  ¼ teaspoon ground black pepper
• •
  Flour, All-Purpose, White(30g)
• •
  Low Sodium Beef Broth(240g)
• •
  Worcestershire Sauce(15g)

  Lea & Perrins is the standard. A little goes a long way.

• •
  Thyme, Fresh
• •
  1 dried bay leaf
• •
  Peas And Carrots, Frozen, Mixed

Instructions

1. 1Peel the russet potatoes and cut into 1-inch chunks. Place in a medium saucepan, cover with cool water by 1 inch, and bring to a boil over high heat. Uncover, reduce heat to medium-low, and simmer until fork-tender, about 12–16 minutes. Drain well and return to the saucepan. If excess moisture remains, heat over low heat for 1 minute, shaking occasionally, then remove from heat.
2. 2Mash the potatoes with a potato masher until smooth. Add the butter, Parmesan, salt, and pepper; stir until butter is mostly melted. In a small bowl, whisk together the milk and egg yolk. Stir into the potatoes until fluffy and combined.
3. 3Heat the olive oil in a large skillet over medium-high heat until shimmering, about 1–2 minutes. Add the onion and cook until beginning to brown, about 3 minutes. Add the fresh garlic and tomato paste; stir continuously for 30 seconds.
4. 4Add the ground beef, salt, and pepper to the skillet. Cook over medium-high heat, breaking apart the meat, until browned and no longer pink, about 4 minutes. Drain excess grease if necessary.
5. 5Sprinkle the flour over the beef and stir continuously for 1 minute over medium heat. Pour in the beef broth and Worcestershire sauce, scraping the bottom of the pan to release browned bits. Add the fresh thyme, bring to a boil over medium-high heat, then reduce to low. Cover and simmer until the sauce thickens slightly, about 10 minutes. Remove thyme sprigs, then stir in the frozen peas and carrots.
6. 6Transfer the meat mixture to a 9×9-inch casserole dish and spread into an even layer. Spoon the mashed potatoes over the top, spreading gently into an even layer to seal the edges.
7. 7Place the casserole on a parchment-lined rimmed baking sheet. Bake uncovered at 400°F for 25 minutes until the potato topping begins to brown and the edges show golden color.
8. 8Remove from the oven and cool for at least 10 minutes. Divide evenly into 6 portions for serving, or store in airtight containers for meal prep.