Prepare all ingredients by washing and cutting vegetables, mincing garlic and ginger, and having everything ready before cooking.

In a small bowl, whisk together soy sauce, oyster sauce, cornstarch, chili garlic sauce, brown sugar, beef broth, and rice vinegar until smooth.

Heat a large wok or skillet over high heat until it begins to smoke slightly, then add vegetable oil and swirl to coat.

Add ground beef, breaking it apart and letting it cook undisturbed for 2-3 minutes to develop a brown crust before stirring.

Continue cooking beef, stirring frequently, until completely browned and cooked through, about 5-7 minutes total, then remove to a plate.

Add broccoli florets to the same pan and stir-fry for 2-3 minutes until bright green and slightly tender but still crisp.

Push broccoli to one side, add bell peppers and onions, cooking 2-3 minutes until they begin to soften but maintain crunch.

Create a well in center of vegetables, add minced garlic and ginger, cooking 30 seconds until fragrant.

Return cooked ground beef to pan, toss everything together, then pour prepared sauce over the mixture.

Stir continuously for 1-2 minutes until sauce thickens and coats all ingredients evenly, then drizzle with sesame oil.

Remove from heat, garnish with chopped green onions, and serve immediately over steamed jasmine rice.