Make the dressing: Add ½ cup creamy peanut butter, ⅓ cup soy sauce, ¼ cup lime juice, 2 tablespoons maple syrup, 2 teaspoons ginger (grated), 1 to 2 cloves garlic (grated), and 2 teaspoons sriracha to a bowl or blender. Whisk or blend until smooth, then add water, 1 tablespoon at a time, until the dressing is creamy, pourable, and coats the back of a spoon. Set aside.
Cook the noodles: Bring a large pot of unsalted water to a boil. Add 8 ounces soba noodles and cook according to package instructions (usually 4 to 5 minutes) until al dente. Do not overcook. Drain the noodles immediately into a colander. Run cold water over them while tossing and rubbing the noodles with your hands for 60 seconds. This removes excess starch and prevents clumping. Drain thoroughly.
Coat the noodles first: Place the drained, cold noodles in a large mixing bowl. Pour about ¾ of the peanut dressing over the noodles and toss thoroughly until evenly coated. If the sauce feels too thick, add a splash of water and toss again until silky and glossy.
Add veggies: Add 1 can chickpeas (rinsed), 3 cups red cabbage, 1 cup cucumber, 1 red bell pepper, and 2 green onions to the bowl. Pour the remaining dressing over the vegetables and toss everything together until well combined.
Garnish and serve: Transfer to a serving bowl. Top with the cilantro and roasted peanuts for crunch. If you like, finish with a drizzle of toasted sesame oil for extra nutty flavor and a final squeeze of lime to brighten everything up.
