In a bowl, mix 2 tbsp oyster sauce, dark soy sauce, 1½ tbsp fish sauce, honey, chicken bouillon, ½ tsp black pepper, and baking soda. Add the beef and coat well. Set aside to marinate.
In a separate bowl, mix 2 tbsp oyster sauce, brown sugar, 1½ tbsp fish sauce, soy sauce, and ¼ tsp black pepper. This will be the garlic noodle sauce—set aside.
Cook the noodles until al dente according to package instructions, then drain and set aside.
Heat a griddle or large skillet over medium heat. Melt the butter with 1 tbsp cooking oil, then add the chopped garlic and sauté until softened and fragrant. Add the noodles, pour the garlic noodle sauce over, and toss until evenly coated. Cook 4–5 minutes until the sauce is absorbed. Remove and set aside.
Increase heat to high. Add 2 tbsp cooking oil and sauté the minced garlic until fragrant. Add the marinated beef and spread evenly to sear each side until golden, about 90% cooked. Add the onions and bell pepper, tossing briefly so they stay crisp-tender.
Reheat the garlic noodles if needed, garnish with green onions, and serve alongside the shaken beef.
