To marinate beef:
Mix rice wine and soy sauce in a large bowl and add cornstarch gradually while whisking constantly. Slice beef into thin pieces and place into bowl with marinade stirring to coat. Let marinate for at least 30 minutes.
Prepare garnish by heating 1 tablespoon of the oil in a saute pan, reserving the other 4 tablespoons. Add the Sichuan peppercorn and dry chili and cook until the chili turns dark red. (Do not allow it to turn black.) Remove the cooked peppercorn and chili to a cutting board and use the side a large chef's knife blade to smash it. Then chop it into pieces and transfer to a small dish. Keep the saute pan handy for the final touches.
Prepare vegetables by washing and cutting celery, leeks, and lettuce into 3-inch lengths. Heat the 2 tablespoons of corn oil in a wok, add scallions and stir once. Add the celery, leeks, and lettuce and stir-fry for 20 seconds over high heat. Remove and place in a large shallow serving bowl.
To cook beef, heat the 1/4 cup corn oil in the wok and add ginger, scallion, and chili sauce. Cook until the oil turns red from the chili. Add wine, soy sauce and stock. When the mixture begins to boil, add marinated beef and gently stir to cook. As soon as beef is completely cooked, remove from wok and place beef over vegetables in serving bowl and pour sauce from wok over it.
Heat the remaining 1/4 cup of oil for the garnish in the saute pan, and when it begins to smoke slightly, pour the oil over the Sichuan peppercorns and chili in the small dish.
Serve everything immediately.
Recipe courtesy of Shirley Cheng, M.S.,CHE, Professor in Culinary Arts, Culinary Institute of America