tablespoons cornstarch, mixed with 2 tablespoons water
teaspoon oyster sauce (optional)
teaspoon sesame oil
In wok or large deep-sided skillet, warm peanut oil over medium-high heat. Add garlic, black bean sauce, ginger and salt; toss and stir until fragrant, about 1 minute.
Raise heat to high, add asparagus, onion and bell pepper. Toss and stir until coated with oil and sauce, about 1 minute.
Add chicken and cook, tossing, until opaque and firm, about 3-5 minutes. Add chicken broth, soy sauce, sugar and chili; bring mixture to a boil, cover and cook additional minute until asparagus is tender but still crunchy.
Add cornstarch mixture and oyster sauce, if using. Cook, stirring continuously, until sauce thickens, about 30 seconds to 1 minute.