1 tablespoon cornstarch
3 tablespoons Chinese Shaoxing rice wine, dry sherry or white vermouth
1 pound beef sirloin, thinly sliced against the grain into strips
Kosher salt and freshly ground pepper
2 tablespoons oyster sauce
2 teaspoons toasted sesame oil
3 to 4 tablespoons peanut oil
1 1-inch piece fresh ginger, thinly sliced
2 cloves garlic, smashed
5 to 7 dried red chiles, halved
1 small onion, thinly sliced
8 heads baby bok choy, halved
Pinch of sugar
Cooked rice, for serving