1. Cook pasta in a large pot of boiling salted water until tender but firm. Rinse under cold water to chill; drain well. Place in a serving bowl; add vegetables and green onions.
2. Dressing: In a bowl whisk together peanut butter, soya sauce, vinegar, sesame oil, brown sugar, ginger, garlic and chili paste. Pour over pasta mixture; toss well to coat. Sprinkle with coriander.