Cook your pasta in salted boiling water just until tender, slightly softer than al dente. Once done, drain and rinse it under cold water to stop cooking and wash off extra starch.
In a large bowl, whisk together lemon juice, lemon zest, white balsamic vinegar, Dijon, salt, pepper, capers, and chopped walnuts. Slowly drizzle in the olive oil until everything is well combined.
Add the cooled, rinsed pasta into the bowl with the lemon dressing. Toss gently so every piece gets coated with that bright, tangy dressing.
Finally, toss in the fresh arugula. The arugula might wilt slightly from the warm pasta and absorb all the citrusy flavors.
