This is an updated version of a recipe originally published on April 27, 2003. This was also my Feast Asia column on May 20, 2009.
As common as it may be, the curious thing about sweet and sour sauce is just how many versions there are. I remember my mother (who wasn’t a good cook at all) trying to replicate the restaurant version of my favorite dipping sauce for lumpiang shanghai by mixing together flour, soy sauce, sugar and vinegar. Perhaps, it was just her but cornstarch never seemed to figure among her ingredients for sweet and sour sauce. Naturally, with flour instead of cornstarch, the resulting sauce had a cloudy appearance.
When I became a teenager and started getting seriously interested in Chinese cooking, I learned about cornstarch and, after that, tapioca starch or what 1980s Canadian TV personality Stephen Yan liked to call Wonder Powder. I used either to make sweet and sour sauce and, instead of soy sauce, I added a little tomato paste (sometimes ketchup) for color. I used this formula happily for almost three decades and no one who tried it could find fault.
But as with most anything else, a cook never stops to find better and better recipes. I learned recently that the best sweet and sour sauce does not contain any starch. The thick texture is the result of boiling vinegar and palm sugar together until the mixture reaches the syrupy stage. Super fine strips of ginger are added for spice, aroma and bite. Below is a recipe for sweet and sour fish where the sauce is made using the described procedure.
Serves 4 to 6.
1 whole white, firm and fleshy fish, about 1.5 kg., scaled and gutted
salt and pepper
1 tbsp. of cornstarch or tapioca starch
3 c. of vegetable oil for deep frying
For the sweet and sour sauce:
1 c. of rice vinegar
1-1/2 to 2 c. of shaved palm sugar (or dark brown sugar)
½ tsp. of salt
1 tbsp. of very fine strips of ginger
For the garnish:
1 onion, finely sliced (or 12 stalks of onion leaves, cut into 2-inch lengths)
1 small carrot, julienned
a thumb-sized piece of ginger, julienned
1 tbsp. of sesame seed oil
Make the sweet and sour sauce. Place the vinegar and sugar in a small pan and set over medium heat. Cook without stirring until the sugar dissolves. Swirl the pan and boil over medium heat for 15 to 25 minutes or until syrupy. Add the salt and ginger during the last five minutes of cooking.
While the sauce cooks, prepare the fish. Heat the cooking oil in a wok or frying pan. Pat the fish dry with paper towels. Cut three to four diagonal incisions about half an inch deep on both sides of the fish (what is referred to as “scoring”). Season the fish with salt and pepper, rubbing inside the cavity and incisions. Dust with cornstarch or tapioca starch.
When the oil is hot enough (it should start to emit some smoke), deep fry the fish over high heat until golden and a light crust forms on the outside. Flip the fish when the underside is done and fry the other side for even cooking and texture. Scoop out the fish and drain on paper towels. Transfer to a serving platter and scatter the prepared garnishes on top. Pour the sweet and sour sauce over the fish and vegetables.
Heat the sesame seed oil in a small pan until smoking. Pour over the fish and vegetables. Serve at once.