Spiced Parsnip Shepherd's Pie

Preheat the oven to 200°C/400°F. Place a 9x13 inch baking dish on a rimmed baking sheet to catch any potential bubbling over later.

Place the chopped parsnips and russet potatoes into a large pot and cover with cold, generously salted water. Bring to a boil over medium-high heat, then lower the heat and maintain a vigorous simmer until completely fork-tender.

While the roots are boiling, heat the olive oil in a Dutch oven over medium heat. Add the diced onion, carrots, and celery. Sauté until softened and the onions are translucent.

Increase the heat to medium-high and add the ground lamb. Break it apart with a wooden spoon and sear until fully browned, ensuring no pink remains and an internal temperature of at least 74°C/165°F is reached for safety. Drain excess fat if there is more than a thin layer coating the bottom.

Add the minced garlic, thyme, and tomato paste to the lamb mixture. Stir continuously and cook until the tomato paste darkens to a brick red. Sprinkle the plain flour over the mixture and stir well to coat the meat, cooking out the raw flour taste.

Pour in the beef broth and Worcestershire sauce, scraping the bottom of the Dutch oven to release any browned bits. Bring to a simmer, then lower the heat. Allow the gravy to reduce and thicken significantly until it elegantly coats the meat.

Remove the Dutch oven from the heat. Fold the frozen peas into the hot lamb mixture. Taste for seasoning and add salt and pepper as needed. Set aside to cool slightly.

Thoroughly drain the boiled parsnips and potatoes. Return them to the hot, empty pot off the heat for two minutes to let excess steam evaporate. Pass them through a potato ricer into a bowl. Crush together with the butter, warmed heavy cream, ground cumin, coriander, nutmeg, and salt until deeply smooth and flavorful.

Transfer the slightly cooled lamb filling into the 9x13 inch baking dish, spreading it into an even layer. Spoon the spiced parsnip mash in dollops over the top, then gently spread it out to the edges to seal the meat entirely.

Using the tines of a fork, heavily score the surface of the mash. The resulting peaks and ridges will catch the heat in the oven, creating extra crispy, golden-brown bits.

Bake in the preheated oven at 200°C/400°F until the gravy bubbles visibly around the edges and the scored mash is heavily browned and crisp on top.

Remove the pie from the oven. Let it rest undisturbed before serving. This crucial resting phase allows the gravy to stabilize and absorb back into the meat, yielding perfectly coherent scoops.