1. Wash the onion and finely chop the garlic into minced garlic, and chop the ginger into minced ginger and set aside.
2. Put an appropriate amount of butter in the pan, add onion, garlic, and ginger until fragrant.
3. Pour in an appropriate amount of water and bring to a boil.
4. Pour it into the food processor and stir until it is mushy, then pour it back into the pot and cook.
5. Pour in an appropriate amount of crushed black pepper, white pepper, tomato sauce, salt, sugar, oyster sauce, and dark soy sauce and stir evenly.
6. Finally use cornstarch + water to adjust the thinness of the black pepper sauce.
7. This fragrant black pepper sauce is complete.
