Easter feast: Indian-spiced roast leg of lamb a crowd-pleasing treat

I roast a leg of lamb about twice a year. Almost invariably, one of those times is Easter. I like it because it is large enough to feed a crowd and, if it is butter­flied, it does not take that long to grill (either over coals outside, or under the grill element of an oven), leaving plenty of time to prepare side dishes and dessert.

Indian spice and yogurt-marinated leg of lamb

Have the butcher butterfly the leg of lamb, rather than just removing the bone. When it is butterflied, the lamb is more even in thickness. As always with a large cut of meat, I strongly advise using a meat thermometer, preferably a battery-operated probe type, that will beep when the meat reaches the correct temperature.

The spice mix is adapted from a version by one of my favourite food writers, J. Kenji López-Alt, from the website Serious Eats, who uses it for tandoori game hens. His spice mixture makes enough for two legs of lamb but it is worth making the entire amount, rather than halving the recipe; store the excess in an airtight container and freeze it for another occasion.

If you are making this for dinner tonight, the first thing to do is to rush out this morning and buy your butterflied leg of lamb and any other ingredients you might need. As soon as you get home, sprinkle the lamb with salt and let it sit at room temperature for at least an hour. This gives you plenty of time to make the spice mix, and several hours to marinate the lamb before it’s time to cook dinner.

1 butterflied leg of lamb, about 2kg
Fine sea salt, for sprinkling

For the spice mixture:
12 grams whole cumin seeds
5 grams whole coriander seeds
20 grams smoked paprika
4 grams ground turmeric
1 gram ground cayenne
12 grams achiote/annatto seeds
8 garlic cloves
A 10cm chunk of fresh ginger, peeled and roughly chopped
50 grams fine sea salt
60ml fresh lemon juice
250 grams whole milk Greek yogurt