My children love this. Actually, I don’t know anyone who’s eaten it and doesn’t. While it’s spicy (though you can reduce the heat to taste) and vibrant, it is also cosy and comforting, and blends the familiar with the less traditional in a way that gives me quiet satisfaction.
The impetus to use a sweet potato mash for the topping was simply because it was so much easier than peeling and mashing regular potatoes, and they work so well against the hot, exuberantly spiced meat, especially when tempered with lime and ginger juice.
For US cup measures, use the toggle at the top of the ingredients list.
FOR THE TOPPING:
- 1 kilogram sweet potatoes
- 2 teaspoons sea salt flakes
- 2 x 15ml tablespoons white peppercorns
- 6 cardamom pods (cracked)
- peeled strips from 1 unwaxed lime and juice of ½ lime
- approx. 1 litre cold water
- 4 centimetres piece fresh root ginger (peeled) – plus more for filling (see below)
FOR THE FILLING:
- 3 cloves garlic (peeled)
- 4 centimetres piece fresh root ginger (peeled)
- 1 onion (peeled)
- seeds from 6 cardamom pods
- 2 teaspoons cumin seeds
- 2 teaspoons coriander seeds
- 2 x 15ml tablespoons cold-pressed coconut oil
- 2 teaspoons garam masala
- 1 teaspoon dried chilli flakes
- 1 teaspoon ground turmeric
- 500 grams minced lamb
- 1 x 400g can chopped tomatoes
- 100 grams red lentils
- 1 teaspoon sea salt flakes
- 2 x 15ml tablespoons worcestershire sauce
- Preheat your oven to 220°C/200°C Fan/gas mark 7/425°F. Start with the topping, cutting each of the sweet potatoes into approx. 4-5cm / 2in chunks.
- Put the unpeeled potato chunks into a large saucepan (with a lid) and add the salt, peppercorns, cracked cardamom pods and lime strips (you don’t need the ginger just yet), then add just enough cold water (about 1 litre/4¼ cups) to cover.
- Bring to the boil, then reduce the heat slightly, put the lid on and cook for about 30 minutes – or until the sweet potato is tender – while you get on with the filling.
- Slice the garlic and ginger roughly, quarter the onion, and put them all into the bowl of a food processor with the cardamom, cumin and coriander seeds, and whizz until finely chopped. Alternatively use a bowl and a stick blender, or just chop everything very finely by hand.
- Heat the coconut oil in a heavy-based pan (with a lid), and then tip this paste in.
- Cook for a few minutes or so to soften, stirring frequently, then stir in the garam masala, chilli flakes and turmeric, and tip in the lamb mince, turning it in the spiced onion mixture and breaking it up gently.
- Add the chopped tomatoes, then fill the empty can with cold water and, swilling it around, pour this in as well. Stir in the red lentils.
- Season with the salt and worcestershire sauce, then bring to a bubble, clamp on the lid, lower the heat and simmer for about 25 minutes, stirring once or twice to stop it catching on the bottom of the saucepan.
- When the sweet potatoes are cooked, drain them, reserving the liquid, and leave until cool enough to peel away the skins. Put the flesh into a wide bowl.
- Mash the sweet potatoes, using a potato masher, or any gadget of your choice (even a fork would do) and slowly beat in some of the potato cooking water – adding as much as you need to make the mash a less dense, more spreadable consistency – and squeeze in the juice of half the lime. Grate the peeled ginger onto a plate – I use a coarse microplane grater – then spoon the grated ginger into the centre of a piece of kitchen roll. Moving quickly, pull up the edges of the paper and twizzle them, so you have a little wrapped swag-bag, then squeeze and wring out over the mash (an intense ginger juice will drip out). Beat this juice into the mash below. Check the seasoning, tasting to see if you want any more lime or ginger, too.
- Once the lamb filling has had its time, ladle equally between 4 small ovenproof bowls or dishes of approx. 400ml / 1½-2 cups capacity (or a larger rectangular dish, measuring approx. 30 x 20 x 5cm deep / 12 x 8 x 2 in deep and 1.6 litre / 6 cups capacity), and then top with the mash, also dividing this equally between the bowls, spreading it to cover the rim of the dishes.
- Sit the dishes on an oven tray and place in the oven for 10-15 minutes (or, if you’re cooking this in one larger dish, it will need 30-35 minutes). The mash should be piping hot (though it won’t get a crust) with the mince bubbling underneath.
- On serving, sprinkle 1 teaspoon of nibbed pistachios over each bowl.