In a medium pot of boiling water, cook the ramen noodles according to package directions until al dente. Drain, rinse under cold water until cool, then drain well; transfer to a large bowl.
In a small bowl, combine tahini, oil, vinegar, ginger, miso, garlic and cup of water. Season with salt and pepper and whisk until smooth.
Add cup of the dressing to the noodles, season and toss to coat. Add chickpeas, sliced vegetables, scallions and remaining dressing; season and toss to coat. Serve at room temperature or chilled.
