To make a really, really crap white sauce you should first spend the entire day shouting at your children. You should take care in particular to shout such things as ‘I said don’t shout at me’. This last should be done in the backyard so that you can be sure you sound like a complete idiot to people you have never met. Your hair should be at the exact length and at the exact time in the washing cycle where it hangs in your eyes but can not be brushed away. You should be wearing clothes which did not have one last wear in them, and should have been put in the washing last night.

Take your saucepan out of the sink and wash out the guck from two nights before. Use the dishcloth which is starting to get that certain feel and that certain smell. Don’t make the saucepan sparkling clean, just clean enough so that you can be fairly sure you won’t get botulism. Leave the cloth in a wet mess on the bottom of the sink to be dealt with later on.

Just before you are about to pour in the milk, answer the phone even though no one you know or love would be ringing at this time. Let the person on the other end make you feel badly for cutting them short. Have another glass of wine, even though you have told yourself that this is the week you will not drink, of course you do not need wine to get you through the night.

Return to the saucepan, add the milk, watch the lumps form, make a half-hearted effort to squeeze them out, pour a bit more milk in. Rinse the spinach while the sauce overheats. Give a half-hearted stir with a metal soup spoon. Let the sound grate on you, but do not stop straight away. Allow every black thought you have ever had about yourself to swirl between your ears. Invent a few new ones. If you have trouble with this, you aren’t trying, and your white sauce will not be truly crap.

This white sauce will destroy your lasagne. To end the evening, curse yourself for ruining a dish which takes a fair amount of time and a large portion of your week’s best vegetables.

On the other hand, to make a good – a very good – white sauce you should take the perfectly-sized saucepan which you will find washed and put away exactly where it should be. As is the lid, although you do not need it tonight. Turn the radio down. Further down. Just a little bit more.

Do not worry that the children are being exceptionally loud. They are enjoying each other’s company and spending the kind of time from which they will one day draw their motivations to succeed or otherwise, the strength they will need to mend their first broken heart, and the odd dinner-party laugh.

Heat the saucepan over a gentle flame, and scoop the butter in at exactly the right time. Watch its colour change as it melts. Take in the smell. Close your eyes if you wish, but only for an instant. That is all you need. Sprinkle in the flour, and although you have not measured either the butter or the flour, you will get it exactly right. The flour does not have the maggots of pantry moths. Pour in half a cup of milk and watch as no lumps appear. Feel it thicken. Add a little more milk, and then a little more. Listen to the gentle rub of the spoon against the bottom of the saucepan and watch the trail of the spoon through the sauce. Stir and watch and stir and watch and stir and watch some more. Listen to the sound of the flame and for no reason at all think of camping trips.

Remove from the heat at exactly the right time. Use to make a tuna mornay. Pay no attention to the parts of your brain which normally tell you that the oceans are over-fished and that tuna have dangerously high levels of certain heavy metals which you would prefer that your children didn’t ingest.

Enjoy your meal.