In a large bowl, combine 1 tablespoon of the oyster sauce, the soy sauce, 1 teaspoon of the wine, sugar, pepper flakes and 1 teaspoon of the cornstarch, whisking to dissolve the cornstarch.

Add the pork and toss to coat. Marinate for 15 to 30 minutes.

In another bowl, make the sauce by combining the remaining tablespoon oyster sauce, 1 teaspoon wine, 1 teaspoon cornstarch, and the chicken broth, whisking to dissolve the cornstarch. Set aside.

Place a large wok over high heat until hot. Add the oil, swirling to coat the sides and bottom.

Add the garlic and cook for 10 seconds.

Add the pork and stir-fry until lightly browned, about 2 minutes.

Add the onions and peppers and stir-fry for 1 minute.

Add the celery and the mushrooms and stir-fry for 1 minute.

Add the bean sprouts and water chestnuts, stir to mix well and cook until crisp-tender.

Make a well in the center and add the sauce and chili paste.

Cook, stirring, until the sauce boils and thickens and the pork is cooked through, 1 to 2 minutes.  

Remove from the heat and serve over noodles or white rice. Garnish with green onions and serve.