In a small bowl, whisk together soy sauce, oyster sauce, rice wine vinegar, ginger, garlic, cornstarch. set aside.
Heat olive oil in a large skillet over medium-high heat. Add the broccoli and cook for 4-5 minutes or until tender.
Remove the broccoli from the pan; place it on a plate.
Add the remaining oil to the pan. Season the shrimp with salt and pepper to taste and add them to the pan. Cook for 3-4 minutes, stirring occasionally, until pink and opaque.
Add the garlic to the pan and cook for 30 seconds. Add the broccoli back into the pan.
Stir in soy sauce mixture until well combined and slightly thickened, about 1-2 minutes.
Serve immediately, garnished with green onion, if desired.