I'm still on the hunt for some old school Thai food in Bangkok, and today I chose to venture to the other side of the Chao Praya River to a place with a long history. My friend the Peranakan Baba had done an extensive tour of old school establishments in the city 2 months ago, and Tek Heng (เต็กเฮง, 符德興) was one of the places he found. Apparently the Teochew family has been running this place for more than 130 years, and is famous for having served their mee krob to King Chulalongkorn back in the day.
the one I had at Chote Chitr. Texture-wise the fried noodles were pretty crunchy and hard, and the flavors were deeper and more intense. The tanginess comes from the peel and juice of a citrus fruit called som sa (ส้มซ่า), which can be a little bitter. Very, very good.