Cook the pasta: Bring a large pot of salted water to a boil. Cook pasta until just al dente, then drain and rinse briefly under cool water to stop cooking.
Shake off excess water.
Prep the chicken: Shred or dice cooked chicken. If using raw chicken, season with salt, pepper, and a pinch of smoked paprika, then sear or bake until cooked through. Let it cool before chopping.
Mix the dressing: In a bowl, whisk Greek yogurt, olive oil, lemon juice, red wine vinegar, Dijon, honey, garlic, oregano, salt, and pepper.
Taste and adjust acidity or salt as needed.
Chop the veggies: Dice bell pepper and cucumber, halve tomatoes, and finely chop red onion. Slice olives and chop parsley. If using frozen peas, thaw by rinsing under cool water.
Combine: In a large bowl, add pasta, chicken, vegetables, olives, peas, and parsley.
Pour in most of the dressing and toss gently until everything is coated.
Add cheese and finish: Fold in feta. Add remaining dressing if needed for creaminess. Season with extra salt, pepper, or lemon juice to brighten.
Chill or serve: For best flavor, chill 20–30 minutes to let the flavors mingle.
Garnish with extra herbs. Add avocado right before serving if using.