Turkey berry is fondly called as "sundaikai" in Tamil is a popular household product with regard to the people of Tamil Nadu. If any day no stock of vegetables at home, sundaikai does all the work.
Fresh green or dried brown it is immensely used in Traditional Tamil cuisine. Fresh are used in sambhars, made into pickles (curd soaked) and It is also used as a vegetable to prepare curry.
where as the dried one are also added in sambhar but it is particularly used in KHADAMBAM (a variety rice prepared during the KANNUM pongal,-the next day of Thai pongal) and Vatha kuzhambu (A spicy sambhar made without cooked dal).
Sundakai is also made into powder by grinding it together with roasted red chillies and urad dal.
Here is the recipe of turkey berry sambhar : : https://anuradhasowmyanarayanan.stck.me/post/34303/TASTY-SAMBHAR-WITH-TURKEY-BERRY
Scientifically it is proved that Sundakai /turkey berries are typically tangy and bitter, they are great to control blood sugar levels, and prevent the onset of type-2 diabetes. Turkey berries boost the body's immunity from common ailments like cold, cough and the flu.