The most impressive part of Onam celebration is the grand feast called Onasadya, prepared on Thiruonam. It is a nine course meal consisting of 24 - 28 dishes served in it.. Onasadya is served on banana leaves and people sit on a mat laid on the floor to have the meal.
Onasadya is a big feast associated with a special occasion, such as a marriage, birthday, childbirth etc. Onasadya is traditionally a vegetarian meal served on a plantain or banana leaf; people eat sitting cross-legged on the floor.
The dishes are plain boiled rice, many curries, papadum, plain yogurt or buttermilk, banana or plantain chips, and two or more sweet dishes. The curries are made of different vegetables and have different flavourings. They can be made of yogurt, bitter gourd, mango, jaggery, etc. The reason for including so many dishes in the Sadya is to ensure that the diners will like at least two or three dishes. Coconut, being abundant in Kerala, is used in almost all dishes. Coconut milk also finds various uses in cooking. Coconut oil is used for frying.
There is a specific place for each item on the plantain leaf. For example, the pickles are served on the top left corner and banana on the bottom left corner. Thus, the waiters can easily identify the requirement of the diner by just looking at his leaf. There are variations in the menu according to the place and the religion. Onion and garlic are not typically used in the sadya.
The sadya is usually served as lunch. Preparations begin the night before, and the dishes are prepared before ten o' clock in the morning on the day of the celebration. All the dishes are served on the plantain leaf; it requires a special skill to eat the food. The food is eaten with the hands without use of any cutlery.
Traditionally, the people of the neighbourhood spent the night helping the cooks in works like scraping coconut and cutting vegetables. These people also volunteered to serve the food to the guests. This lent a personal touch to the occasion. Enterprise and urban demands on time and space have now made it possible for the work to be contracted to professional catering services.
Conventionally, the meal may be followed by vettila murukkan, chewing of betel leaf with lime and arecanut. This helps digestion of the meal and also cleanses the palate.
The usual items in Onasadya are:
Parippu : A thick lentil dish eaten with rice, papadum and ghee.
Sambar : A thick gravy made of lentils, tamarind, coconut, vegetables like drumsticks, tomato, etc., and flavored with asafoetida.
Rasam : A watery dish made of tamarind, tomatoes, and spices like black pepper, asafoetida, coriander, chili pepper, etc. It is very spicy in taste and aids in digestion.
Aviyal : Thick mixture of various vegetables, yogurt, and coconut. It is seasoned with coconut oil and curry leaves. This dish is usually made of leftover vegetables.
Kaalan : Made of yogurt, coconut, and any one vegetable like "nendran" plantain or a tuber-like yam. It is very thick and more sour than avial.
Olan : A preparation of pumpkin, coconut milk, and ginger seasoned with coconut oil.
Koottukari : One or two vegetables like banana and coconut with a hot and sweet taste.
Kichadi : Made of yogurt and cucumber in raw or cooked form.
Pachadi : A sweet form of kichadi, but made with pineapple, grapes and coconut.
Injipuli : Curry made of ginger, tamarind, green chilies, and jaggery.
Thoran : A sauteed dish of vegetables such as peas, green beans, raw jackfruit, carrots, or cabbage (usually) with grated coconut.
Pickles (Achar) : Spicy pickled raw mango/lemon/lime, etc.
Pradhaman is a sweet dish in the form of a thick liquid; similar to payasam, but with more variety in terms of ingredients and more elaborately made. It is made with white sugar or jaggery to which milk or coconut milk is added.
· Palada pradhaman is made of flakes of cooked rice, milk, and sugar.
· Pazha pradhaman is made of cooked "nendra" plantain in jaggery and coconut milk.
· Gothambu pradhaman is made of broken wheat.
· Parippu pradhaman is made of green gram.
· Chakka pradhaman is made of jackfruit.
· kadala pradaman is made from black gram.