The Zhengxing Street morning market operates from around 6am to noon in the streets south of the old city core, and it is one of the most local food experiences available in Tainan. The market is a working neighbourhood market rather than a tourist attraction, and the stalls reflect what Tainan people actually eat for breakfast: milkfish congee served in large clay pots, rice porridge with side dishes, sweet potato congee, tofu pudding, soy milk, and steamed buns. The milkfish — ufishe, in the local term — is Tainan's most emblematic ingredient, farmed in the coastal ponds west of the city, and the congee version with its soft fish belly and light broth is one of the best morning meals available anywhere in Taiwan.
Go early: the best stalls sell out by 9am, and the market energy is at its peak between 7 and 8. Bring cash and be prepared to point if your Mandarin is limited — the vendors are accommodating, and the food speaks clearly enough for itself.