Finely dice 3 medium onions and a couple of handfuls of mushrooms and grate 2-3 carrots on the large setting.

Sauté the onions in some oil until really nice and soft, then add the carrots and mushrooms. Season as you go with salt and freshly ground pepper. Sweat everything down and add some fresh thyme and rosemary (don’t go too mad with the rosemary, a couple of sprigs’ worth is fine). Add minced lamb and cook till the mince is brown and the fat has rendered out.

Add a couple of tablespoons of flour and stir in. When the flour is cooked, add a tablespoon of Marmite, a few glugs of Worcestershire sauce and stir. Add enough stock (lamb or beef) to cover and reduce it down. Let it bubble away for a couple of hours until it’s very tender and the gravy is thick, adding more water if necessary. You can add frozen peas if you like at this point. Don’t rush it. When cool, divide among the dishes you’ll cook your shepherd’s pie in and refrigerate.

Chop and boil some floury potatoes and mash when completely tender. Mash with butter and salt and pepper but no milk/cream - makes it too soft. Gently spoon over the lamb mince, which should be set. This keeps the layers separate rather than the mash sinking into the mince. Carefully even out the top, then rake it with a fork, you can make patterns if you like. Sprinkle with a handful of mature cheddar cheese.

Bake at 180-200 C - 400F about 25 min until the cheese is golden and the mince is bubbling up around the edges and making little pools of gravy.

You can sub the lamb mince for beef if you’d rather make cottage pie instead. You can make the lamb mince ahead and freeze but I recommend topping with mash before you cook it - cold mash takes a long time for the heat to penetrate and it’s better fresh, in my opinion.