In a mixing bowl, combine the soy sauce, oyster sauce, cornstarch, and chicken broth. Whisk until the cornstarch is fully dissolved, and set the sauce aside.

Heat the vegetable oil in a wok or large skillet over medium-high heat until shimmering.

Add the minced garlic, sliced bell peppers, and onion to the wok. Stir-fry for 2–3 minutes, or until the vegetables are just tender yet crisp.

Toss in the shrimp and continue stir-frying for another 2–3 minutes, until the shrimp turn pink and are just cooked through.

Pour the prepared sauce into the wok. Toss everything to coat evenly and cook for an additional 1–2 minutes, stirring until the sauce thickens and coats all components.

Serve immediately while hot, ideally accompanied by steamed rice.