Cook the pasta: Bring a large pot of salted water to a boil. Cook the pasta until just al dente. Reserve 1/3 cup pasta water, then drain and rinse under cool water to stop the cooking. Toss with a splash of olive oil so it doesn’t stick.

Season and sear the beef: Pat the beef dry and season with salt and pepper. Heat 1 tablespoon olive oil in a skillet over medium-high. Sear beef in batches, 1–2 minutes per side, until browned but still tender. Transfer to a plate to rest.

Make the dressing: In a bowl, whisk mayonnaise, Greek yogurt, lemon juice, Dijon, honey, and red pepper flakes. Stir in garlic and Parmesan. Thin with a splash of reserved pasta water until creamy and pourable. Taste and adjust salt and pepper.

Prep the vegetables: Halve cherry tomatoes, slice red onion, and chop greens and parsley. Keep them bite-size for easy eating.

Combine: In a large bowl, add cooled pasta, beef (slice any large pieces), tomatoes, onion, greens, and parsley. Pour over most of the dressing and toss gently to coat.

Adjust: Add more dressing as needed. If the salad looks dry, loosen with a little pasta water or a drizzle of olive oil. Finish with extra Parmesan.

Rest and serve: Let it sit 10–15 minutes so the flavors meld. Serve slightly cool or at room temperature.