Scoring the fish serves multiple purposes. Firstly, it allows for more even cooking by helping heat penetrate the flesh. Secondly, it helps the fish cook faster. Thirdly, scoring creates crevices that catch the sauce, enhancing flavor absorption. Lastly, it adds an attractive presentation with crispy, textured edges.
Using cornstarch in the dry rub serves to create a light coating on the fish, aiding in achieving a crispier texture when fried. It also facilitates better adherence of the sauce to the fish. However, if you prefer not to use cornstarch, you can opt for all-purpose flour. While all-purpose flour can also create a crispy texture when fried, it may not be as light and airy as cornstarch. Cornstarch tends to result in a slightly crispier coating due to its finer texture and ability to absorb less oil. Additionally, you can experiment with other starches, like rice flour or potato starch. Rice flour tends to create a lighter and crunchier texture, while potato starch can produce a denser and slightly chewier coating compared to cornstarch. Each starch behaves differently and can offer a unique twist to the dish. Now, If you choose to omit cornstarch or any starches from the dry rub, the texture of the fried fish might be slightly different again.
While you can use store-bought sweet and sour sauce as a convenient option, preparing the sauce from scratch is recommended for a more authentic and flavorful experience. Homemade sauce allows for greater control over the taste and freshness of the dish, enhancing its overall quality.