The sweet and sour sauce is perfectly balanced, with crispy-coated beef slices that are tender and juicy on the inside.
My uncle-in-law is an excellent cook, and every weekend he would go to my grandmother's house to cook, with his signature dish being crispy flash-fried beef slices. The meat was mostly fatty, coated in a water starch slurry, then deep-fried vigorously until it made a crackling sound when poured onto the plate, followed by the sizzle of oil on the surface—just how crispy was that? A sweet and sour sauce was prepared, brought to a boil in the wok, thickened with a slurry, and hot oil added, causing the edges to bubble up. With a loud sizzle, the sweet and sour aroma filled the air. The meat slices were tossed in, quickly stir-fried a few times, sprinkled with a handful of minced garlic, and then taken off the heat! The rich, smoky fragrance of the fatty meat combined with the sweet and sour flavor was nothing short of magnificent. This dish had to be served as the grand finale, because if left to sit for even a moment, it would become limp and greasy.
Ingredients
Main Ingredients
200 g (about 7 oz) beef tenderloin
Beef tenderloin or leg meat, using a relatively tender cut.
Seasonings for sweet and sour sauce
soy sauce 10 g (about 2 teaspoons)
30 g (about 2 tablespoons) rice vinegar
30 g (about 2 tablespoons) sugar
30 g (about 2 tablespoons) water
1 g salt
Other Seasonings
5 g (about 1 teaspoon) Shaoxing rice wine
Scallion and ginger, to taste
150 g (about 1 1/4 cups) cornstarch
Always use cornstarch, as it creates a crispier texture than other starches, making it ideal for deep-frying.
Instructions
Instructions
Marinate the beef: In a bowl, combine the sliced beef with 1 tablespoon soy sauce, 1 tablespoon Shaoxing wine, 1 teaspoon cornstarch, and 1/2 teaspoon white pepper. Mix well and let sit for 15 minutes.
Step 1: Remove the sinew from the beef, then slice it into pieces about 10 cm long, 6 cm wide, and 0.3 cm thick (approximately 4 x 2.5 x 1/8 inches) and set aside (Image 2).
*The beef should not be sliced too thin, or it will lose its meaty flavor after frying.
② Slice some scallions and ginger, then soak them in a bowl to make scallion-ginger water (Image 3). Place the beef slices in a bowl, add Shaoxing wine and a pinch of salt, and mix well. Then gradually add the scallion-ginger water in batches, mixing thoroughly each time to allow the beef to fully absorb the liquid (Image 4).
*This marinating method differs from the one used for stir-frying; the beef will be more tender if it absorbs more moisture, and since it will be coated in batter and deep-fried, there's no need to worry about moisture loss. However, don't add too much water—the beef slices should not release water and should feel slightly sticky to the touch for the best results.
Mix cornstarch with water to create a slurry.
③ Place cornstarch in a bowl, mix with water to form a paste, add a little oil, then stir by hand until smooth and elastic (Image 5).
*The key step is preparing the starch slurry—make sure it’s not too thin. When adding water, start with a small amount and mix, then add a little more and mix again, gradually reaching a point where the starch forms a large clump, even slightly dry. Then firmly knead the clump with your hands until it becomes smooth. If it feels too dry, add a tiny bit more water, then add a little oil and continue kneading until the mixture flows off your hand in a thick, unbroken stream.
Deep-fry the beef slices
④ Pour plenty of oil into the wok and heat to around 350-375°F (medium-high heat). Evenly coat the beef slices with the starch paste (Image 6), then add them to the oil. Deep-fry over medium-high heat until the surface is set and lightly golden, then remove and drain.
*After evenly coating the beef slices with the starch batter, the surface should be covered in a white batter; if too much red meat is visible, the batter is too thin and hasn't adhered properly.
Add the beef slices one at a time, working quickly but not all at once to prevent them from clumping together. During frying, once they are slightly set, use chopsticks to separate any slices that have stuck together.
*Since the pan at home is small and there's limited oil, frying the beef slices in two batches will yield better results.
5. Heat the oil in the wok again until it reaches about 80% hot (350°F/175°C), then add the deep-fried beef slices back in for a second fry until the surface is firm and golden brown (Figure 7), then remove and drain.
*Re-frying a second time is a crucial step for achieving a crispy exterior—do not skip it.
Combine the sauce ingredients, then pour over the flash-fried beef slices.
Pour the sweet and sour sauce mixture into the wok and bring to a boil, then thicken with cornstarch slurry until the sauce is slightly viscous (Image 8).
*Do not use too much slurry—aim for a consistency similar to a light soup; if it's too thick, it won't coat the beef slices evenly.
Pour some of the hot oil used for deep-frying the beef slices into the wok, then add the fried beef slices and stir-fry until the sauce coats the surface evenly (see Figure 9).
*Adding a small amount of hot oil helps maintain the temperature, better releases the sweet and sour aroma, and assists the sauce in coating evenly while giving the surface a glossy sheen—cold oil cannot achieve these effects.
A versatile technique: adjust the thickness of the beef slices and the vinegar-to-sugar ratio to suit your preference, and feel free to swap in other proteins like pork loin or chicken breast.
The flash-fry method works well with many meats, such as fish fillets, shrimp balls, pork, and chicken. For a savory version, simply omit the sugar and vinegar when preparing the sauce.
A lazy cook's trick
If you find it too troublesome or difficult to prepare the starch batter, after marinating the beef (using less water), simply toss it with beaten egg, then coat it directly in dry starch before frying—the remaining steps are the same. This method is much easier, but the crust won't be as crispy, so you'll need to eat it as quickly as possible, or it will soften soon.