As I have stated earlier and I re-iterate being a vegetarian in Turkey is not a problem or a chore it is a pleasure, I find apart from the wonderful selection of fresh vegetables, fruits, pulses etc., for sale in local shops and markets, the restaurants and locantas are more than helpful, I've even been invited into kitchens to see how meals are prepared and speak to the chefs.
Most locantas have the food on display in ranges (the Megri locanta in Fethiye I find is one of the best), with a mouthwatering display of dishes suitable for vegetarians.
If all else fails you also have the great standards, delicious salads, pide, jacket potatoes, omlettes etc.