Questions & Answers about Aku ngidam pecel; kita patungan, ya.
It is casual / conversational Indonesian.
Clues:
- aku = informal I
- ngidam = colloquial form
- ya at the end softens the sentence in a friendly way
- patungan is very common in everyday speech
You would use this with friends, family, a partner, or people you are close to. It would sound too casual in a formal setting.
Ngidam is a colloquial shortened form of mengidam.
In everyday spoken Indonesian, especially informal speech, people often reduce meN- verbs:
- mengidam → ngidam
- menonton → nonton
- mengobrol → ngobrol
So ngidam is very natural in speech and texting, while mengidam sounds more standard or formal.