Paiwan Every Day 372: kan // kanen

kanen ni kama azua sinandjamai ni kina. 

In English: 

Dad ate the dishes prepared by mom. 

Glossary: 

1. kan-en: eat, undergoer voice (UV). The root is kan 'eat'. 
2. ni: of, genitive (GEN) case marker, used as the subject case marker of a UV verb. 
3. kama: father
4. s<in>an-djamai: vegetable cooked by, UV. san- 'to work on'; the root is djamai 'vegetable'. 
5. kina: mother

Reading: 

From CIP Online Paiwan Dictionary kanen. 

kina naluku too likes to makes UV sentences when she speaks Paiwan. UV can be roughly understood as passive. Why?