Chinese Mongolian Beef

Instructions

1. Prepare the beef
   Place the sliced beef in a large bowl and toss with cornstarch until each piece is fully coated. Let it sit for 10 minutes to allow the cornstarch to adhere properly.
2. Prepare the sauce
   In a small bowl, whisk together the soy sauce, brown sugar, minced garlic, grated ginger, water, and sesame oil until the sugar is fully dissolved. Set aside.
3. Fry the beef
   Heat the vegetable oil in a large wok or skillet over high heat. When the oil is hot but not smoking, add the beef in batches and cook for 1-2 minutes per side until crispy and browned. Remove and drain on paper towels.
4. Cook the sauce
   Pour out all but 1 tablespoon of oil from the wok. Add the sauce mixture to the pan and bring to a simmer. Cook for 2 minutes until the sauce begins to thicken.
5. Combine and finish
   Return the beef to the wok and add the green onions and red pepper flakes if using. Toss everything together until the beef is well coated and the green onions are slightly wilted, about 1 minute.
6. Serve
   Transfer to a serving plate, sprinkle with toasted sesame seeds, and serve immediately with steamed rice.