In a measuring cup combine Sherry, oyster sauce, sesame oil, sugar and pepper. Set aside.
Combine cornstarch and water in a small bowl and whisk until smooth. Set aside.
Place wok on medium-high heat for 1-2 minutes.
Add the oil, garlic, ginger and black bean sauce. Stir-fry for 30 seconds.
Add the firm vegetables and stir-fry for 3-4 minutes.
Add the softer vegetables and stir-fry for 2-3 minutes.**
Pour sauce over vegetables, stir to coat and cook 2-3 minutes.
Pour cornstarch-water mixture into wok and immediately stir as the sauce thickens, 1-2 minutes.
Serve on rice or toss with softened rice noodles.
Sprinkle with garnishes of your choice. Serve.