Chop the celery and the white part of the leeks very finely. Melt ½ stick of the butter with the oil in a wide saucepan and cook them gently until softened. In another saucepan, pour in 1 cup of the champagne and all of the chicken stock, and keep on a very low simmer nearby to your risotto.

When the vegetables are soft, tip in the rice and turn in the oil until slicked and glossy. Turn up the heat, pour in the remaining ½ cup champagne and, stirring all the time, let it be bubblingly absorbed.

Turn down the heat slightly but not too low, and keep adding ladles of champagney stock, letting one ladleful be absorbed before adding the next, stirring all the while.

Once the rice is cooked – 18–20 minutes should do it – stop, even if you’ve got some stock left over. Equally, if the rice has absorbed all the stock and yet needs further cooking – both happen – add a little more, or if it’s just a very little more you think you need, boiling water will do.

Off the heat, beat in the remaining butter and the Parmesan. Season with a good grinding of white pepper if possible to keep it looking pure and unspeckled.