Cook pasta in large pot of boiling salted water until tender but still firm to bite.
Drain pasta, rinse in cold water and drain thoroughly. Place in a large bowl.
Mix with olive oil. Seed tomatoes and chop coarsely.
Slice peeled broccoli stems 1/4 inch thick and break florets into smaller pieces. Cook 3 minutes in boiling water. Drain, rinse in cold water and drain again.
Add tomatoes, broccoli, olives and walnuts to the pasta and toss gently.
Serve with pesto dressing
In a blender or food processor, chop the basil, garlic, walnuts, Parmesan cheese and vinegar.
Add the olive oil in a slow stream until it is all combined. Stir in salt and pepper.