The heat question
Pedas atau tidak? ‘Spicy or not?’
You will be asked. If you are not asked, assume spicy. Indonesian pedas is calibrated to people who have eaten chilli since childhood, and “a little spicy” from a warung will not match your idea of it.
Tidak pedas. ‘Not spicy.’
Sedikit pedas. ‘A little spicy.’
Say it when you order. Chilli is usually cooked in, not added at the end.
The phrase that does everything
Tidak pakai means ‘without’, literally ‘not using’. It attaches to anything.
Tidak pakai gula. ‘Without sugar.’
Tidak pakai es. ‘Without ice.’
Tidak pakai sambal. ‘Without chilli sauce.’
In speech this becomes nggak pakai or, shortest of all, nggak pake.
Allergies and restrictions
Saya alergi kacang. ‘I’m allergic to peanuts.’
Peanuts are worth knowing specifically: kacang is in satay sauce, in gado-gado, in pecel, and in many things that do not announce it.
Saya tidak makan daging. ‘I don’t eat meat.’
Saya vegetarian. ‘I’m vegetarian.’
Be aware that vegetarian is often understood as “no red meat”, and that fish sauce and shrimp paste terasi are in a great deal of cooking. If it matters, name the ingredient rather than the category.
Pork, and where you are
Babi ‘pork’ is absent from most Indonesian menus, and asking about it in a Muslim area is awkward rather than offensive.
Bali is the exception, where babi guling is a signature dish. Knowing which island you are on is part of knowing which questions to ask.