O-a chian (蚵仔煎, Taiwanese: o-ah-chian, Hokkien pronunciation of oyster omelette) is the most iconic of Taiwan's night market street foods and one of the defining preparations of Fujianese cooking — a crispy-edged, slightly gooey omelette made from fresh oysters, beaten eggs, and a sweet potato starch slurry that creates an almost glutinous, sticky interior. The final dish is topped with a sweet-spicy sauce (typically a mix of ketchup, miso, and chilli sauce) and fresh coriander. The texture — simultaneously crispy-edged and gooey-centered — is one of the most distinctive in Chinese street food.
The starch slurry: 2 tbsp sweet potato starch (地瓜粉, di gua fen) + 3 tbsp water. This starch produces a more glutinous, sticky texture when cooked than cornstarch — it is the key to the characteristic gooey center. The cooking: Heat 2 tbsp lard (traditional) or oil in a flat skillet over medium-high heat. Add 6-8 small fresh oysters (or larger ones halved). Let them sizzle and begin to caramelize at the edges. Pour the starch slurry over the oysters. It will immediately begin to set. While still wet, pour 2 beaten eggs (seasoned with salt and white pepper) over the starch layer. Fry until the egg begins to set on the edges. Flip the entire omelette. Continue cooking 1-2 minutes until the egg is cooked through and the underside is lightly crispy. The sauce: 2 tbsp ketchup, 1 tbsp white miso (or yellow bean paste), 1 tbsp sugar, 1 tbsp water, 1 tsp chilli sauce. Cook together briefly until combined. Pour over the completed omelette.
Fuchsia Dunlop, Invitation to a Banquet (2023)