A winter medley of flat beans, purple yam, sweet potato, baby aubergine and plantain, slow-cooked with fenugreek dumplings and a green masala of coconut and coriander.
Muthia: fried dumplings of gram flour and fresh fenugreek.
A green masala of coconut, coriander, green chilli and ginger.
Cooked slowly with little water, so everything steams in oil.
Where it comes from
The name comes from the Gujarati for upside-down: it was cooked in a clay pot, a matlu, sealed and buried upside-down in a fire pit. Surat is its home, and the flat beans of the region, surti papdi, are what it must have.
It's eaten in winter, when the beans and yams are in season, and especially around Uttarayan, the kite festival in January, when families eat it with puri and jalebi on the rooftops between kites.
How it varies
Kathiyawadi undhiyu
A red, hotter version with chilli and garlic instead of the green masala.
Matla undhiyu
Still made the old way in clay pots buried in fire, sold by roadside cooks around Surat.