In a large sauté pan with a tight fitting lid, whisk miso, soy, vinegar, sriracha, ginger, and garlic.
Add scallions, snow peas, peas, edamame, carrots, spaghetti, broth, salt and pepper.
Cover and cook, over medium heat, 15 to 20 minutes, stirring occasionally until pasta is done and broth is mostly absorbed. Start checking for doneness around 10 minutes.
Toss to distribute sauce and veggies. Garnish with sesame seeds and serve from the pan, family style, at the table.