Slice beef against the grain into ¼-inch slices or ½-inch sticks. Place in a bowl, add soy sauce, peanut oil, and cornstarch (plus baking soda if using), and mix gently. Marinate 10 minutes.

In a medium bowl, whisk together chicken stock, Shaoxing wine, both soy sauces, brown sugar, and cornstarch until smooth.

Add ¼ cup water to a large skillet over medium-high heat. When boiling, add broccoli, cover, and steam for about 1 minute until just tender. Transfer to a plate and wipe skillet dry.

Heat oil in the skillet over medium-high heat. Spread beef in a single layer, cook undisturbed for 30 seconds, flip, then stir-fry until lightly charred but still pink inside.

Add garlic and ginger, stir briefly until fragrant.

Return broccoli to the skillet. Stir sauce again to dissolve cornstarch and pour it in. Stir-fry until sauce thickens and coats everything, about 1 minute. Serve immediately.