Bring a large pot of water to a boil. Salt the water, then add the somen and cook until al dente, 3 to 4 minutes. Rinse under cold water. Drain well and divided noodles among 4 serving bowls
Heat 1 Tbsp vegetable oil in a large skillet over high heat. Add the garlic and carrots and cook for 2 to 3 minutes. Add the zucchini and a little more oil if needed. Cook, stirring occasionally, until the zucchini is just slightly browned. Turn off the heat, add the green onions, and toss
Stir in the soy sauce, sesame oil, and sugar together in a small bowl until the sugar dissolved
Top the noodle with bulgogi (if using). Pile the vegetable mixture next and drizzle with the soy mixture. Top with the cucumbers, sesame seeds, and black pepper. Serve immediately
Notes
VARIATONS: If you're feeling more adventurous, experiment with other vegetables. Mushrooms, onion, bell peppers, and sprouts work well