Prepare the Aromatics: Finely chop 3 cloves of garlic and a small piece of ginger, and thinly slice 1 small onion.
Stir-fry the Meat: In a wok or large pan, heat 1 tablespoon of oil over high heat. Add the chopped garlic and ginger, and stir-fry until fragrant. Add 200 grams of meat (beef, chicken, or seafood) and stir-fry until it is just cooked through. Remove the meat from the pan and set aside.
Stir-fry the Vegetables: In the same pan, add 1 more tablespoon of oil if necessary. Add the sliced onion and stir-fry until it starts to soften. Then add 1 cup of mixed vegetables (such as bok choy, broccoli, bell peppers, and carrots) and stir-fry until they are tender but still crisp.
Combine Meat and Vegetables: Return the cooked meat to the pan with the vegetables. Add 2 tablespoons soy sauce, 1 tablespoon oyster sauce, 1 teaspoon fish sauce, salt, pepper to taste, and 1 teaspoon sugar. Stir well to combine and cook for another 1-2 minutes.