Slice the chicken thinly across the grain into 1/8-inch pieces—this ensures tender, quick-cooking bites. In a bowl, combine the sliced chicken with 2.5 tablespoons cornstarch, 1 teaspoon salt, and 1/2 teaspoon white pepper. Toss gently to coat evenly; this velveting technique creates a silky, tender texture. Meanwhile, prepare all your vegetables: peel and slice the carrot into thin rounds, trim the snow peas, slice the mushrooms, and drain the water chestnuts and bamboo shoots. Mince the garlic and ginger and set aside. Having everything prepped before cooking is essential since stir-frying happens quickly.
Heat 1 tablespoon of vegetable oil in a large wok or skillet over high heat until it shimmers. Working quickly, add the velveted chicken mixture from Step 1 and cook for about 30 seconds per side—you're not fully cooking it here, just searing the exterior to seal in juices and develop flavor. The chicken will finish cooking later when it returns to the pan. Transfer the chicken to a clean plate and set aside.
Add the remaining 2 tablespoons of vegetable oil to the same pan over high heat. Add the carrot slices, snow peas, and mushrooms, stirring constantly for about 3 minutes until they begin to soften and develop light color. Then add the water chestnuts, bamboo shoots, minced garlic, and minced ginger from Step 1, stirring for another minute until fragrant. I like to add the garlic and ginger near the end of vegetable cooking so they stay vibrant and aromatic rather than turning bitter—it makes a noticeable difference in the final flavor.
Return the seared chicken from Step 2 to the pan with the vegetables. Pour in the chicken stock, soy sauce, sugar, and sesame oil, stirring gently to combine. Bring the mixture to a boil and let it cook for 1-2 minutes, allowing the flavors to meld and the chicken to finish cooking through.
While the pan is simmering, mix the remaining 1.5 tablespoons of cornstarch with 1.5 tablespoons of water in a small bowl to create a slurry. Pour this mixture into the pan and stir constantly for about 1 minute until the sauce thickens and coats the chicken and vegetables with a silky glaze. The starch will transform the loose sauce into something velvety that clings beautifully to each component. Taste and adjust seasoning with salt if needed. Serve immediately over steamed rice.