Marinate the beef: Toss sliced steak with soy sauce, cornstarch, and baking soda. Let it rest for 10 minutes.
Prepare the sauce: Whisk together soy sauce, oyster sauce, brown sugar, sesame oil, black pepper, sriracha, and red pepper flakes.
Cook the broccoli: Heat oil in a wok. Stir-fry broccoli for 2 minutes, then remove from pan.
Sear the beef: In the same pan, add more oil. Sear steak on high heat for 2 minutes until browned.
Add aromatics: Stir in garlic, ginger, and fresh chili, cooking until fragrant.
Combine everything: Pour the sauce into the pan. Stir in the cooked broccoli.
Thicken the sauce: Add cornstarch slurry and cook for 1 minute until glossy.
Serve hot: Enjoy with rice or noodles and a glass of water if the heat gets too real.