Prepare all ingredients. Cut potatoes into small bite-sized cubes, slice bell peppers into small pieces, smash and finely chop garlic, grate ginger to about 1 teaspoon, and thinly slice green onions, keeping the white and green parts separate.
2
Prepare the sauce by combining soy sauce, oyster sauce, sugar, chicken bouillon powder, dark soy sauce, Shaoxing wine, black pepper, cornstarch, and water in a small bowl. Stir well and set aside.
3
Heat 2 tablespoons of oil in a large wok or pan over medium-high heat. Add potato cubes, season with salt, and sear for about 8 minutes until they turn golden brown and are cooked through. Remove and set aside.
4
Add 1 tablespoon of oil to the same wok and heat over high heat. Add ground beef, spread it evenly, and sear for 1-2 minutes. Flip, break up the meat, and stir-fry for about 3 minutes until cooked through and the fat is rendered.
5
Add garlic, ginger, and the white parts of green onions to the meat. Sauté over medium-high heat for 1-2 minutes until fragrant.
6
Add the cooked potatoes and bell peppers, stirring for about 1 minute until everything is evenly coated with the aromatic oil.
7
Stir the sauce well, then pour it into the wok and stir-fry everything together for about 1 minute until evenly coated with a glossy sauce.
8
Turn off the heat, add sesame oil, and toss everything together one final time. Transfer to a serving plate and garnish with the green parts of green onions and cilantro if desired.