Garcinia binucao is a species of flowering plant in the Clusiaceae family. It is commonly known as binukaw, batwan or batuan, is a species of Garcinia endemic to the Philippines. It is not cultivated, though its edible fruits are harvested from the wild for use as a souring agent in some Filipino dishes.

Batwan, also known as batuan or Garcinia binucao, is a fruit that is commonly used in Filipino cuisine, particularly in the Visayas and Mindanao regions of the Philippines. It belongs to the Garcinia family and is known for its sour taste and unique flavor. Batwan is an essential ingredient in many traditional Filipino dishes, imparting a tangy and citrusy flavor to soups, stews, and sauces.

Here are some examples of how batwan is used in Filipino cuisine:

1. Sinigang:
Sinigang is a popular Filipino sour soup that features a tamarind-based broth. In certain regions, batwan is used as an alternative souring agent in sinigang. The fruit is added to the soup to provide a tangy and acidic taste, balancing the flavors of the meat or seafood and vegetables.

2. Kare-Kare:
Kare-Kare is a traditional Filipino stew made with oxtail, tripe, or vegetables in a rich peanut sauce. Batwan is sometimes added to the dish to enhance the sourness and add a hint of citrusy flavor to the sauce.

3. Pinangat:
Pinangat is a Filipino dish made with fish or shrimp cooked in a sour broth of tomatoes, ginger, onions, and spices. Batwan is often used to provide the souring agent in this dish, resulting in a zesty and flavorful broth.

4. Sinampalukang Manok:
Sinampalukang Manok is a chicken soup dish made with tamarind leaves and other aromatics. In some variations, batwan is used instead of tamarind leaves to achieve the desired sourness.