I really enjoyed my (free!) food tour with Balkan Bites and our guide, Mirella. The tour is tip-supported, but all the "bites" (and sips!) along the way are included. You'll also receive a wealth of information about Bulgarian food, culture and history while walking through the city center. Definitely tip generously and try to revisit any of the stops that interest you for more than a bite! Tours run daily at 2pm, reservations are recommended (required on the weekends). Further details can be found here: https://balkanbitesfoodtours.com/