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
Whisk the cornstarch with 2 tablespoons rice wine in a medium bowl; add the beef, season with salt and pepper and toss to coat. Set aside for 15 minutes.
Mix the remaining 1 tablespoon rice wine, the oyster sauce and sesame oil in a large bowl; set the bowl near the stove.
Heat a wok or large nonstick skillet over high heat until very hot, about 1 minute. Add 3 tablespoons peanut oil, then the ginger, garlic and chiles; stir-fry until fragrant, about 1 minute. Add the beef and cook, stirring or shaking the skillet occasionally, 1 to 2 minutes. Transfer the beef with a slotted spoon to the sauce mixture and toss.
If the pan is dry, add 1 tablespoon peanut oil, then add the onion and stir-fry until just soft, about 2 minutes. Add the bok choy and sugar; stir-fry until just wilted, 1 to 2 minutes. Return the beef and any juices to the pan and stir to combine. Serve over the rice.