How to Make It
In a very large skillet, heat the oil. Season the meat with salt and pepper and sear the pieces over moderately high heat until richly browned all over. Transfer the meat to a large slow cooker, turn it to high and cover.
Wipe out the skillet and return it to the burner. Add the soy sauce, sugar, wine and stock and bring to a boil. Pour the mixture into the slow cooker. Add the onions, cover and cook for 2 hours. Add the garlic and jalapeños to the stew, cover and cook for 1 hour longer, until the meat is very tender.
Meanwhile, bring a medium saucepan of water to a boil. Add the bean sprouts and blanch for 30 seconds; drain. Put the cornstarch in a bowl and whisk in 1/2 cup of the liquid from the cooker.
With a slotted spoon, pick out and discard the onions. Transfer the meat to a large bowl. Whisk the cornstarch mixture, then whisk it into the stew, cover and let simmer for 2 minutes. With 2 forks, very coarsely shred the meat. Return the meat to the cooker. Add the Napa cabbage and pickles to the cooker, cover and cook until the cabbage is just wilted, about 5 minutes. Turn the cooker off.
Spoon steamed rice into bowls. Ladle the stew over and around the rice. Top with the beans sprouts, a drizzle of sesame oil and the sliced scallions and serve.