The Secret of the Grain (French: La graine et le mulet, lit. 'the grain and the mullet'), titled Couscous in the UK, is a 2007 Franco-Tunisian drama film directed by Abdellatif Kechiche. The film stars Habib Boufares as an aging immigrant from the Maghreb whose ambition to establish a successful restaurant as an inheritance for his large and disparate family meets sceptical opposition from the French bureaucracy.

The French title of the film refers to a "grain of couscous" and to mullet, a type of small fish, both popular in Tunisian cuisine. The two ingredients constitute both the staple of his extended family's diet and the menu on which he plans to establish his restaurant.