For the peanut sauce, you'll need:
100 gr peanut (fry them without using oil until it's kinda brownish)
1 tbs palm sugar
1 tsp fish paste (if there's an Indonesian market in your town, ask for "terasi")
2 cm galiangale
How to make the peanut sauce:
Put the peanut sauce ingredients into food processor until it is smooth, and then add tamarind water and a little bit of water. The sauce has to be thick enough, so don't add to much water. Then add a little bit of soy sauce (or "kecap manis") to make the colour nicer.
Mix it with your veggies.