Caramelised Onions: The Long Cook

Caramelised onions appear in every tradition in your database — French soupe à l'oignon, Turkish pilav base, Persian rice dishes, Palestinian musakhan, Indian biryani. The technique is universal and universally under-executed: the process takes 45–60 minutes minimum at medium-low heat, not the 10 minutes most recipes claim. Ottolenghi's musakhan onions are the Levantine exemplar of the technique taken to its full depth.

Onions cooked at medium-low heat in generous oil or fat for 45–60 minutes until they have collapsed completely, turned a deep amber-brown, and become sweet, jammy, and intensely flavoured through Maillard reaction and caramelisation of their natural sugars.

Properly caramelised onions are one of the foundational flavour builders of world cooking — they add sweetness, depth, and umami simultaneously. In musakhan they are so abundant they are effectively a sauce in their own right. Their Maillard compounds interact with sumac's tartaric acid to produce a flavour combination that is the taste of Palestinian cooking.