I usually don't try Asian restos in Prague, as I try to find out who serves the best duck + dumpling + Kozel cerny (oh the dark beer!) combo. To name one that's superb is Hergetova Cihelna in Mala Strana on the west-bank of the river just north of the Charles Bridge.

Having said that, I tried Malaysian at a place just west of Prague Castle in Hradcany, and the lunch I had was sufficiently spicey to my liking.

However, seeing as Prague is becoming more frequent for me, I'll have to keep an eye out for Asian restaurants.