Yesterday I was wandering around Linz with a friend and we stumbled upon Pandana. The entry is set back from the Hauptplatz, so it's central, but relatively quiet.
Staff was polite, portions were generous, the food was delicious, prices were appropriate (€11-14 for mains). I had the duck red panang curry; my friend had a vegetarian green curry. (Both were rated one chili. I like spicy food and found it pleasant. My friend's nose was runny.) There were signs up for weekday lunch specials. The only negative thing: the table was a bit wobbly.
We'd happily return.