In a medium bowl, rub the zucchini with 1 teaspoon salt; let stand for 15 minutes. Squeeze the zucchini to remove excess liquid, then pat dry with a kitchen towel.
Meanwhile, in a small bowl, whisk together the gochujang, soy, sugar, vinegar and ¼ teaspoon pepper.
In a 12-inch skillet, combine the oil and garlic. Cook over medium-high, stirring and flipping the garlic, until golden, 2 to 3 minutes. Remove and reserve the garlic; heat the oil until barely smoking. Add the zucchini in an even layer and cook, stirring once or twice, until well browned, 5 to 7 minutes. Add the mushrooms, bok choy, carrot and toasted garlic. Cook, stirring often, until wilted, about 3 minutes. Add the gochujang mixture; cook, stirring, until the vegetables are tender-crisp and glazed, 1 to 2 minutes. Off heat, taste and season with salt and pepper. Serve sprinkled with the sesame seeds.
