Zest the lemon and set the zest aside. Squeeze at least 1/4 cup of lemon juice into a separate bowl.

Make the dressing by mincing 2 garlic cloves and whisking together with the lemon juice, olive oil, dried oregano, salt, pepper, and a pinch of lemon zest until fully combined.

Place chicken thighs in a zip-top bag. Add half the dressing plus 1 more minced garlic clove. Massage to coat, then refrigerate for at least 30 minutes.

While the chicken marinates, cook pasta according to package directions. Drain and let cool completely before assembling.

Heat a skillet over medium heat. Cook the marinated chicken thighs about 5 minutes per side until well browned and cooked through to an internal temperature of 165 degrees F. Remove and let rest for 5 minutes, then chop into bite-sized pieces.

Dice the cucumber and bell pepper. Halve the tomatoes and olives. Roughly chop the parsley leaves.

Add cooled pasta to a large bowl. Top with cucumber, bell pepper, tomatoes, olives, parsley, and chopped chicken. Crumble feta over top, add a pinch of lemon zest, pour the remaining dressing over everything, and toss to coat. Serve immediately or refrigerate until ready.