1 lb (450g) flank steak or sirloin, thinly sliced against the grain

1 tbsp soy sauce (plus extra for sauce)

1 tsp cornstarch

½ tsp baking soda (optional, for tenderizing)

1 large yellow onion, thinly sliced

2 garlic cloves, minced

1 tsp fresh ginger, grated

1 tbsp oyster sauce (or mushroom sauce for vegetarian option)

½ tsp sugar

2 tbsp neutral oil (avocado or sunflower)

2–3 tbsp water or broth (to thin sauce if needed)

Optional garnish: sesame seeds, green onions