In a small bowl, whisk together the miso, rice vinegar, neutral oil, seasme oil, and lemon juice. Season to taste with black pepper. Set aside.
Cook the pasta in boiling water according to package directions. Drain, and rinse under cool water. Give it a gentle shake to get rid of excess water. Place the pasta in a large bowl with the peppers and cucmbers. Drizzle with some of the miso dressing, a little at a time (you may have leftover dressing), and toss to coat. Serve topped with green onions and sesame seeds. Enjoy!