For almost two weeks in the month of August or September, the entire South Indian state of Kerala is closed for business, and open for feasting. The occasion? Onam, Kerala’s most iconic festival, and the setting for one of India’s most delicious feasts: the Onam sadhya.

A harvest festival that takes place in Chingam, the first month of the Malayali calendar, Onam is also said to commemorate the mythical ruler Mahabali, a beloved king who defeated the Hindu gods in battle only to be banished to the underworld by Vishnu. In recognition of his just and prosperous reign, however, the gods allow Mahabali to return to his people once a year. People across Kerala celebrate both the harvest and Mahabali’s return by making ornate flowered pookalam designs, dancing the pulikali and kummattikali, and competing in vallam kali or boat races. The most delicious tradition, however, comes on Thiruvonam, the climax of the festival, in the form of the sadhya, meaning “feast” or “banquet” in Malayalam.

Traditionally consisting of more than 26 dishes, Onam sadhya’s elaborate menu includes several different kinds of pickle, fresh and fried bananas, buttermilk, and a variety of papadums. Main vegetable dishes include erissery, pumpkin and beans in coconut gravy; kichadi, okra or bitter gourd in yogurt sauce; and parippu, or boiled lentils, all served over piles of Kerala’s signature matta red rice. While some Hindu communities in Kerala opt for strictly vegetarian fare, other Hindu, Christian, and Muslim celebrants—especially those in the northern part of the state—can’t imagine an Onam feast without karimeen pollichathu (prawn curry) or beef fry.

If you’re lucky enough to be invited to an Onam sadhya, don’t just dig in. The ritual of serving this feast is as intricate as the process of preparing it. Guests are seated on the ground or on benches in rows and eat with their hands from banana leaves. The food is laid out from left to right, and each dish has a specific place on the leaf. Hosts continue to spoon out hot rice to guests as they eat (and eat, and eat). The meal concludes with a variety of sweet, milk-based payasam puddings, and fragrant, digestive paan.

Preparing this massive feast is such a serious affair that, legend has it, in the pre-colonial Malayali state of Travancore, Onam preparations couldn’t begin until the dewan or prime minister emerged from his royal palanquin to slice the first ceremonial vegetable. While the kingdom of Travancore is no more, the legacy of royal Malayali cooking lives on in this yearly feast fit for a king.