In the marvellous film La graine et le mulet (English title: Couscous), a gala dinner to promote a new restaurant is held up when the couscous itself goes missing. No one even considers serving just the fish and the stew. Obviously, the absence of couscous at what is supposed to be a couscous restaurant would be a noticeable flaw. The more important point, however, is the symbolism of the grains. As characters in the film remark, a couscous meal is love; it is family and community. Few other dishes - perhaps not even that close relative of couscous, pasta - carry such strong significance.
The cooking has something to do with it. You also notice from the film - particularly if you are used to the precooked couscous most widely available in the UK - that preparing a new batch to replace the lost couscous will take at least an hour. Souad, the matriarch of a Tunisian family living in the French port of Sète, uses her couscoussière, a kind of double boiler, to steam the grains. She does not cover the top, but she places a cloth or foil round the intersection of the two pots to prevent the escape of steam; from time to time she stirs the grains to keep them separate. It is quite hard for UK shoppers to find couscous that requires this treatment. All we have to do, with the precooked variety, is submerge it in an equal volume of boiling water, cover it for five minutes, and stir it with a little oil or butter.
The production of couscous adds to the mystique - or did, until mechanisation took over. The skill of the female labourers was in working through moistened semolina by hand until it formed little pellets, which they shaped against the sides of their bowls. The grains were then sieved, and then they were dried.
A couscous is an assembly of good things, all of them to be piled on to one plate, with a mass of golden grains at the centre. The stew is simple, though not crude - Souad gets special praise for cooking all her vegetables à point. She includes squash and peppers; more prosaic vegetables, such as carrots and turnips, are also fine. Mutton would be an appropriate meat. I like the spicy lamb sausages called merguez; a combination of chicken and merguez gives you a couscous royal. In the film, the family serves mullet - and this ingredient, too, in a film that is both naturalistic and artful, is charged with meaning.
Then there is harissa, the spicy ingredient of a sauce that diners pour over their meals according to taste. You can find good varieties of harissa in tins and tubes. I also like to make it, but I am still searching for the ideal recipe. My latest version is not bad: it includes roasted red pepper, dried red chillis, cumin, caraway and garlic.
This is a feast. A film title such as Lasagna - not that I have anything against lasagna, one of my favourite dishes - would be far less evocative.