What are these spaghetti-like strings in the rice I got from a Turkish shop?
It's toasted vermicelli.
This dish is called şehriyeli pilav in Turkey, riz bi sh’arieh in Lebanon and Syria, shehrehi yeghintz in Armenia, and reshteh polo in Iran.
The basic idea is that you brown the noodles in a little bit of oil or butter, then add rice and cook basically as you would cook steamed rice.
Below are four sample recipes.  Note that the Persian version (the last in this list) is more complicated, uses a different noodle (a kind that's more common in Iran) and has a crispy bottom.
şehriyeli pilav
riz bi sh'arieh
shehrehi yeghintz - and if you read that article (it's worth a read), you'll learn that this dish was also the inspiration for Rice-A-Roni.  More like the &quot;Yerevani treat&quot;!
reshteh polo