Chhena is just unset curdled milk from which the whey is strained. It is usually used to make sweets and desserts. It is very popular in Bengali cuisine and is used to make rasgulla, rasmalai, chanar payesh, gulab jamun, etc. Unset curd is usually rubbed with palms and turned into soft cheese (which is almost like a paste), which is then used in a variety of sweet dishes.