Step 1

Preheat the oven to 190C/180C Fan/Gas

Step 2

Put the clarified butter in a flameproof casserole (with a lid) that’s big enough to hold the onions in a single layer and place over a high heat. As soon as it’s smoking hot, add the onions, cut-side down: they should sizzle. Sprinkle with the salt. Leave the onions over the heat for 5 minutes, then put the casserole into the oven and roast for 20 minutes.

Step 3

To make the curry sauce, put all the ingredients into a food processor and blitz until smooth.

Step 4

Take the casserole out of the oven and turn the oven down to 170C/160C Fan/Gas Flip the onions over onto their rounded sides. Pour in the curry sauce around the onions, put the lid on the casserole and return to the oven for 25 minutes.

Step 5

Meanwhile, cook the rice and chop the coriander.

Step 6

To serve, drizzle the cream over the onions and sprinkle with coriander. Serve with naan bread, parathas or basmati rice.