Creating this amazing dish is straightforward if you follow these simple steps:

1. Clean the Crabs: Rinse the crabs under cold water. Remove the shell and gills, then cut them into quarters. Pat dry with paper towels.

2. Heat the Oil: In a large wok or frying pan, heat the vegetable oil over medium-high heat until shimmering.

3. Sauté Ginger and Garlic: Add the sliced ginger (and minced garlic, if using) to the pan. Stir-fry for about 30 seconds, until fragrant.

4. Add Crab Pieces: Carefully add the crab pieces to the pan. Stir-fry for about 3-5 minutes, turning occasionally, until they turn a bright orange color.

5. Season the Crab: Pour in the soy sauce, cooking wine, oyster sauce, and sesame oil. Toss to evenly coat the crabs.

6. Stir in Scallions: Add the scallions to the wok and continue to stir-fry for another 2-3 minutes until the scallions are slightly wilted.

7. Add Black Pepper and Sugar: Season with freshly ground black pepper and brown sugar if desired. Toss to combine everything thoroughly.

8. Check for Doneness: Ensure the crab is fully cooked, which should take about 10 minutes in total.

9. Serve: Transfer the stir-fried crab to a serving platter. Garnish with fresh cilantro if you wish.