Bring a large pot of salted water to a boil. Add the bowtie pasta and cook according to package instructions until al dente, about 12–14 minutes. Drain and rinse under cold water.

In a jar or bowl, combine lemon juice, lemon zest, minced garlic, olive oil, Dijon mustard, oregano, salt, and pepper. Whisk or secure jar and shake until emulsified.

In a large mixing bowl, combine cooked pasta, arugula, sliced red onion, and pistachio nuts. Toss gently to blend.

Pour the dressing over the salad and toss until everything is evenly coated.

Fold in Parmesan cheese or feta, taste and adjust seasoning if necessary. Serve immediately for best freshness.