In a medium bowl, combine sliced beef flank (or skirt steak) with baking soda, light soy sauce, peanut oil, and cornstarch. Mix thoroughly to ensure each piece is well-coated. Let the beef marinate for at least 10-15 minutes while you prepare the other ingredients.

In a separate bowl, whisk together chicken broth, oyster sauce, dark soy sauce, sugar, cornstarch, and sesame oil until well-combined.

Heat 2 tablespoons of peanut oil in a large skillet or wok over medium-high heat until shimmering. Gently add the marinated beef in a single layer and cook for about 1 minute until golden brown, then flip and cook for another minute.

In the same skillet, add remaining oil and toss in sliced onion, minced garlic, and grated ginger. Stir-fry for 2 minutes until the onion becomes translucent.

Add asparagus to the skillet, stirring continuously for about 1 minute until it turns a vibrant green.

Give the sauce a good stir to dissolve any settled cornstarch, then pour it into the skillet with the onions and asparagus. Mix thoroughly until the sauce thickens, about 1-2 minutes.

Add the beef back into the skillet, stirring to coat the meat and vegetables in the savory sauce. Serve hot with jasmine rice.