Stumbled onto this by accident when i was broke near bebek. Boğaziçi university cafeteria serves decent full meals for 25 try and nobody checks if you're actually a student - just walk past the campus gates like you belong

The food is basic but filling - rice, vegetables, some meat, bread. Way cheaper than any bebek restaurant where fish costs 400+ try. But here's the kicker - you're eating your 25 try lunch while staring at the same bosphorus views that cost 200 try per person at nearby cafes