Heat the oven to 180°C.

In a small bowl, mash together the softened butter with the curry powder and some salt and pepper.

Peel the onions, then cut into quarters through the root end.

Heat a frying pan over a medium-high heat and toast the whole spices for 1 minute, tossing every now and again, until they’re smelling amazing and the mustard seeds are beginning to pop. Scrape out into a small roasting tin.

Heat ½ tbsp olive oil in the frying pan and lay the onions in on one of their cut sides. Fry for 3 mins, until charred, then flip onto their other cut side and repeat for another 3 mins. Add ⅔ of the butter to the pan. Cook and baste for a minute until the butter is foaming then tip into the roasting tin. Pour in the chicken stock and spoon in the mango chutney and mix well. Cover with foil and put into the oven to roast for 25 mins.

Once the onions are nearly cooked, drizzle ½ tbsp olive oil over the lamb leg steaks, turning to coat them evenly, then season well with salt and pepper on both sides.

Put the frying pan back over a high heat. Once hot, add the lamb steaks and cook for 3 mins on one side, then flip. Cook for 2 mins on the second side then add the remaining curry butter and baste for another minute.

Move the steaks onto a plate, pour over the butter and leave to rest for 5 mins, then slice.

Spoon the onions and sauce onto a serving platter and top with the sliced lamb steaks, then spoon over any butter and resting juices. Squeeze over the lime juice and scatter with mint leaves to serve.