Bring a large stockpot of salted water to a boil. Once boiling, pour in Cavatappi and follow package directions or boil for roughly 8 minutes. Drain.
Wash and halve grape tomatoes, coarsely chop artichoke hearts, saving liquid. Toast walnuts in a 350° oven, until fragrant. Chop parsley, basil and oregano.
To make dressing: Pour liquid from artichoke hearts into a small bowl. Add lemon juice, olive oil, mustard, and salt and pepper. Whisk all.
Once pasta is cooked and drained, add to a large serving bowl. Immediately add dressing and toss.
Toss tomatoes, artichokes, mozzarella Pearls, toasted walnuts, parsley, red pepper flakes, Parmesan, basil and oregano in with pasta. Add additional salt and pepper, to taste.
If you plan to serve all the salad, add the arugula to the bowl and mix all together. If you plan to serve only half, add only half of the arugula and toss. Refrigerate the remaining pasta and arugula, separately. Add remaining arugula to salad just before serving.