Twice‑Baked Potato Shepherd’s Pie

Preheat the air‑fryer oven to 425°F (425°F).

Bake the potatoes for about 55 minutes, or until the interior reaches 200°F (199°F) and the skins are crisp.

While the potatoes bake, heat beef tallow in a sauté pan over medium heat, add the ground lamb, season with salt, and brown the meat, breaking it up as it cooks.

Add the diced carrots, celery, onion, and minced garlic to the pan and sauté until the vegetables release their moisture and become tender.

Stir in a few tablespoons of butter, then sprinkle flour over the mixture to form a roux and cook briefly to eliminate the raw flour taste.

Mix in tomato paste, then deglaze the pan with Guinness stout, scraping up any browned bits.

Add chicken stock, Worcestershire sauce, fresh thyme, and a bay leaf; bring to a boil, reduce to a simmer, and cook until the mixture thickens into a rich stew.

Taste and adjust seasoning with salt, black pepper, and a splash of red wine vinegar; stir in peas and additional carrots for texture and sweetness.

When the potatoes are done, let them cool slightly, cut off the tops, and scoop out the flesh, leaving a thin wall of potato.

Mash the scooped potato with grated cheddar, the egg, softened butter, and a pinch of salt until smooth.

Fill each potato shell with the lamb stew, then pipe a layer of the cheddar‑cheese mash over the top, creating decorative peaks with a star‑tip piping bag.

Sprinkle flaky sea salt and chopped chives over the piped mash.

Return the assembled potatoes to the air‑fryer oven and roast for about 20 minutes, or until the mashed topping is golden and crisp.

Allow the potatoes to rest briefly before serving.