Cut steak in half lengthwise, then cut crosswise on an angle into thin slices. In a medium bowl, combine beef, 1 tablespoon of the soy sauce, 1 tablespoon of the cornstarch, and the sesame oil. Set aside.
To make sauce, in a small bowl stir together vermouth, remaining 1 tablespoon soy sauce, remaining 1 teaspoon cornstarch, black bean garlic sauce, sugar, and crushed chilies; set aside.
Heat a wok or large frying pan over medium-high heat. Toast hazelnuts, stirring, until lightly browned and fragrant, 3 to 4 minutes. Remove hazelnuts from wok and set aside to cool. Increase heat to high.
Pour 1 tablespoon of the peanut oil into hot wok, swirling to coat. Add beef and cook, stirring and tossing until it is barely pink, 1 to 2 minutes. With a slotted spoon, remove to a plate. Reduce heat to medium-high.
Pour remaining 1 tablespoon oil into wok, swirling to coat. Add green onions, ginger, and garlic. Cook, stirring, until fragrant, about 30 seconds. Add green beans and cook, stirring and tossing, until bright green, 30 seconds to 1 minute.
Stir sauce to blend, then add to wok along with beef. Cook, stirring and tossing, until beans are tender-crisp and sauce thickens, 1 to 2 minutes. Serve topped with hazelnuts.
Serves 3 to 4