Mix the chicken stock, sugar, soy sauces, oyster sauce, sesame oil, Shaoxing wine, and white pepper.
Blanch the broccoli for 30 seconds, then remove and drain. Bring the water back to a boil and blanch the shrimp for 15 seconds. Drain—the shrimp should be partially cooked.
Heat a wok over high heat. Add 2 tablespoons of canola oil, then stir in the garlic. Pour in the sauce mixture and bring to a boil.
Add the shrimp and broccoli back in.
Drizzle in the cornstarch slurry and stir until the sauce thickens and coats everything. Adjust the sauce consistency if needed.