In a small bowl, whisk together soy sauce, oyster sauce, cornstarch, and beef broth. Set aside.
Steam broccoli florets for 3-4 minutes until bright green and tender-crisp. Set aside.
Heat 1 teaspoon sesame oil in a large skillet or wok over high heat. Add beef slices in a single layer and cook for 2-3 minutes without stirring until browned. Flip and cook another 1-2 minutes. Remove beef and set aside.
In the same skillet, add remaining sesame oil, garlic, and ginger. Cook for 30 seconds until fragrant.
Pour in the sauce mixture and bring to a simmer. Cook for 2 minutes until thickened, stirring constantly.
Return beef and add broccoli to the skillet. Toss everything together for 1-2 minutes until well coated. Garnish with sesame seeds and serve immediately over cauliflower rice or a small portion of brown rice.