In a large bowl, combine pasta through tomato. Toss to combine. Refrigerate until 10 minutes before ready to serve.
When ready to serve, stir in dressing. Top with avocado and bleu cheese.
1. If making this ahead, toss pasta with small amount of dressing to prevent it from sticking together. Then, just before serving, stir in remaining dressing.
2. If making this ahead, toss diced avocado with fresh lemon juice before adding to salad.