Shepherd's Pie

Boil the potatoes

Boil the chopped potatoes in salted water until a knife slides in with no resistance, about 20 minutes.

Brown the lamb

Fry the minced lamb in a large pan over high heat, breaking it up, until browned all over and no pink remains, about 8 minutes, then drain off excess fat.

Soften the vegetables

Add the onion, carrot, celery and garlic to the lamb and cook until softened, about 8 minutes.

Build the gravy

Stir in the tomato puree, flour, stock, Worcestershire sauce and thyme, then simmer uncovered until it thickens into a rich gravy, about 20 minutes.

Mash the potatoes

Drain the potatoes and mash them with the butter and milk until smooth, seasoning to taste.

Assemble the pie

Spread the lamb filling in a baking dish and top it evenly with the mash, forking the surface into ridges.

Bake until golden

Bake at 200 degrees Celsius until the top is golden brown and the filling bubbles at the edges, about 25 minutes.

Rest before serving

Rest the pie for 5 minutes before serving so the filling firms up.