I have flirted and failed with diets for so long I cannot look at the word these days without being riddled with guilt and self-doubt. I know all the reasons why a sensible diet should be part of my life. I eat too much, liking food for its delicious flavours and tastes, that I just can’t ignore the things I have loved all my life. That makes me a failure too, not being able to provide a regular sort of cooking which is not only healthy but leaves you feeling good, then, during the night and the next morning. I try it on for a while, then fall to temptation.

I have seen people who have succeeded. During the restaurant days, one of my favourite customers was a devotee of the Pritikin diet, a man who was absolutely content to live without butter, cream, eggs, sugar, salt and grog. I looked at him and saw a man with sparkling eyes, of clean skin, a man oozing satisfaction with his life, his lifestyle and his diet.

I was so drawn by his appearance, I went for it with a gusto: on the first day, fruit for breakfast, fruit for lunch, then a big dinner of steamed potatoes pureed with poached onions, chillies and garlic; more steamed vegetables with mint; bowls of mangoes and raspberries; the weakest tea; and no grog. It worked — I felt great, didn’t fall asleep in the after-dinner chair, and bored the pants off everyone else in the house.

I tried it the next day. Fruit, fruit and more fruit during the day, then at dinner: eggless pasta with tomato sauce and snow peas; steamed fish on a puree of spinach, lots of lemon juice and black pepper; apricots, lightly stewed in lemon juice; more intense conversation about the pros and cons of eating to live. Now my wife had fallen asleep in the chair.

The diet failed because: (i) I became a bore, a sort of live-in Billy Graham; (ii) I needed a drink; and (iii) I wanted to celebrate a special occasion and didn’t fancy doing it with mango, mineral water and mumbo-jumbo. Could you? I went back to my worst ways. Absolute worst. Read on and you will understand what I mean.

Buy your prawns from your favourite and trusted fishmonger. Fresh is best, of course, but they are not always available at retail outlets. If not, don’t buy soaked green prawns, buy them frozen and defrost them yourself. There is an argument that frozen prawns can be better than fresh, unless you can get them while they are still kicking. The crux of the argument is this: if they are frozen quickly, preferably straight out of the water, and maintained at the correct minus temperature, then there is no chance of any deterioration. There’s plenty to that argument — as long as you know your supplier.