Blanch the carrots and sugar snaps in boiling water, 2 to 3 minutes, until tender but still crisp, drain. In a wok over high heat, heat canola oil, add mushrooms and stir. Add carrots and sugar snaps, and stir for 2 minutes. Lower the heat and add cabbage, salt and pepper. Sitr in cornstarch slurry, oyster sauce and sesame oil.