Fribourg's restaurant scene is modest but honest. The old town has a handful of good traditional restaurants serving rösti, cheese fondue (Gruyères cheese is made just down the road), and raclette. Prices are Swiss, but not outrageous by local standards.
The student quarter around the university keeps a number of cheaper options open during term time, including canteen-style places where a full meal runs around 8–10 CHF.