Cook the pasta to al dente, then drain and rinse with cold water. This keeps the salad from turning into a hot, sad mush.
Lightly steam or blanch the broccoli until just tender, then plunge it into cold water to stop the cooking. Drain well.
In a large bowl, combine chicken, cooled pasta, broccoli, tomatoes, red onion, and cheese (if using). Toss gently so everything stays pretty.
Whisk together mayo (or yogurt mix), lemon juice, Dijon, and honey. Add salt and pepper to taste. If you want more zing, splash in a bit of pickle juice or extra lemon.
Pour the dressing over the salad and toss until evenly coated. Add herbs last, so they stay fresh and bright.
Chill for at least 30 minutes if you can. Flavor loves a little patience, and so do your taste buds.