Heat the vegetable oil in a wok or large skillet over medium-high heat. Add the garlic and stir-fry until aromatic, about 1 minute.
Cook the Eggs (Optional): Crack the eggs into the pan and stir quickly to break the yolks. Cook until lightly scrambled and just set, about 1 minute.
Turn the heat to high, add the shrimp, and stir-fry until pink and cooked through, about 2-3 minutes. Remove and set aside.
Add the bok choy stems to the pan and stir-fry for 1-2 minutes, followed by the leaves. Cook until tender but still crisp.
Add the cooked spaghetti to the pan. Pour in the Pad See Ew sauce and toss to coat the noodles evenly.
Return the cooked shrimp to the pan and stir everything together until heated through. Season with freshly ground white pepper to taste.
Divide the dish into bowls or plates. Serve hot with optional condiments like chili flakes, fish sauce, or a squeeze of lime.