Heat a wok or skillet. Add 1T vegetable oil. Add thinly sliced beef and sautee until half cooked. Combine soy, hoisin, garlic, sugar, chili, lemon and cornstarch into sauce and add to beef. When glazey, about 1 minute, add salt & white pepper to taste and stir in vegetables. Stir-fry until mushrooms and snow peas are cooked but still crunchy. Serve immediately with plain rice. See note on lemon Zest.