In large pot of boiling water, cook pasta according to package directions. Drain, reserving 1/3 cup pasta water.
Meanwhile, season chicken with oregano, onion powder, dried parsley and half each of the salt and pepper. Heat oil in large skillet set over medium heat; cook chicken and garlic for 8 to 10 minutes or until chicken is cooked through.
Add pasta, reserved pasta water, spinach, olives, lemon juice, and remaining salt and pepper to skillet; cook, tossing to coat pasta, for about 2 minutes or until spinach starts to wilt. Sprinkle feta and parsley over top.
Recipe Notes
For pork souvlaki pasta, substitute pork tenderloin for chicken.