Two tablespoons of cornstarch on a pound of flank steak is what makes this crispy rather than merely browned. The coating fries into a shell, and a third of a cup of oil is enough to shallow-fry it in batches.
Everything after that is arranged to protect the crust. The frying oil is poured off, the sauce is built quickly in what remains, and the beef goes back in only long enough to be coated.
Why This Recipe Works
- Cornstarch fries into a crisp shell far more reliably than flour on a wet surface.
- Frying in batches keeps the oil hot, which is what crisps rather than soaks.
- Pouring off all but a tablespoon of oil stops the finished sauce being greasy.
- Serving the beef over the noodles rather than tossed through them keeps the crust out of the wet.
Ingredient Notes
- Flank steak
- A pound in 1-inch pieces, tossed in cornstarch. Fried to at least 145 degrees Fahrenheit with a three-minute rest.
- Neutral oil
- A third of a cup for shallow frying, then all but a tablespoon poured off before the sauce.
- Cucumber
- Half of one, thinly sliced. Raw and cool against the fried beef, and visible in the finished bowl.
How to Make It
Coat and fry crisp
Toss beef with cornstarch and salt. Heat oil in a wok or skillet and shallow-fry beef in batches until dark, crisp, and at least 145 degrees Fahrenheit; drain.
Cook the noodles
Cook noodles until tender and drain.
Build the sauce
Pour off all but 1 tbsp oil. Cook ginger and garlic 20 seconds, then add soy sauce, sweet chili sauce, vinegar and brown sugar.
Toss quickly
Return crispy beef and toss quickly in the glossy spicy sauce.
Serve over noodles
Serve over noodles with scallion, red chile, sesame and cucumber slices.
Four Moves to Keep the Crust
Everything in this recipe after the frying is designed to get sauce onto crisp beef without turning it soft. Each rung gives up as little of the crust as possible.
Coat
1 lb of flank steak in 1-inch pieces tossed with 2 tbsp cornstarch and 1/2 tsp salt. Cornstarch fries into a shell where flour on damp meat would go patchy.
Fry, in batchesDark and crisp, 145F with a 3-minute rest.
Shallow-fried in 1/3 cup of neutral oil until dark and crisp and at least 145F, then drained. Batches keep the oil hot; a crowded pan steams the coating it is meant to crisp.
Pour off, then build fast20 seconds on the aromatics - the pan is still very hot.
All but 1 tbsp of the oil poured away, then ginger and garlic for 20 seconds and 3 tbsp soy, 2 tbsp sweet chili sauce, 1 tbsp rice vinegar and 1 tbsp brown sugar. Leaving the frying oil in would make the sauce greasy.
Toss, and stop
The beef back in and turned through the glossy sauce for seconds only, then straight over the noodles. This is the moment the dish is won or lost: crust and sauce are opposites, and time is what decides between them.
Success Tips
- Fry in batches. Crowding the pan drops the oil temperature and the coating goes soggy rather than crisp.
- Drain the beef on a rack or paper before it meets the sauce.
- Toss for seconds only — the longer the crust sits in sauce, the less crust there is.
Serving Ideas
Four servings, the crispy beef spooned over yellow noodles with sliced scallion, red chile, sesame seeds and cool cucumber slices.
Frequently Asked Questions
Could this be done in a slow cooker?
No. The beef is shallow-fried until crisp, and no covered cooker produces that texture.
My beef went soft in the sauce.
Toss it quickly and serve straight away. Crisp coating and wet sauce work against each other by design.
How done should the beef be?
At least 145 degrees Fahrenheit with a three-minute rest, as for any whole-muscle beef.
