In a mixing bowl, combine sliced flank steak with soy sauce, peanut oil, cornstarch, and optional baking soda. Marinate for about 10 minutes.

In a large nonstick pan, bring water to a boil. Add broccoli florets and steam for about 1 minute until bright green. Set aside.

Whisk together stock, Shaoxing rice wine, both soy sauces, and cornstarch until smooth. Set aside.

Heat 15ml of peanut oil in the pan over high heat. Add marinated beef, sear for 30 seconds, flip and cook for 10 seconds. Remove from pan.

In the same pan, stir-fry garlic and ginger for 30 seconds until aromatic.

Return beef to pan and add steamed broccoli. Mix gently to combine.

Pour prepared sauce over beef and broccoli, stir to coat, and cook for 1 minute until sauce thickens.

Remove from heat and serve immediately over rice or noodles.