1. Mix together the dressing ingredients.
2. Bring a large covered pan of boiling water to boil then add pasta. Cook as instructed on packet. Five minutes before the end of cooking time, add the asparagus. Drain, rinse under cold water, then drain well.
3. Combine the pasta, asparagus, tomatoes and pecans.
4. Pour the dressing over the pasta and toss well to coat then season with pepper.