Prep the chicken marinade: In a bowl, whisk 2 tablespoons olive oil, 1 tablespoon lemon juice, 1 teaspoon lemon zest, 2 minced garlic cloves, 1 teaspoon dried oregano, 1/2 teaspoon salt, and 1/4 teaspoon black pepper.
Add chicken and coat well. Let it rest while you prep everything else (10–20 minutes is enough).
Cook the pasta: Bring a large pot of salted water to a rolling boil. Add pasta and cook until al dente according to package directions.
Reserve 1/4 cup pasta water, then drain. Toss hot pasta with 1 tablespoon olive oil to prevent sticking.
Make the dressing: In a jar or small bowl, combine 1/4 cup extra-virgin olive oil, 2 tablespoons lemon juice, 1 tablespoon red wine vinegar, 1 teaspoon Dijon mustard, 1/2 teaspoon honey, 1/2 teaspoon dried oregano, 1 small grated garlic clove, 1/4 teaspoon salt, and a few grinds of pepper. Shake or whisk until emulsified.
Taste and adjust lemon or salt.
Cook the chicken: Heat a large skillet over medium-high. Add a thin film of olive oil. Sear chicken 4–6 minutes per side, until browned and cooked through (internal temp 165°F/74°C).
Rest 5 minutes, then slice into bite-size pieces.
Prep the veggies: Halve cherry tomatoes, dice cucumber and bell pepper, and thinly slice red onion. Roughly chop spinach if the leaves are large. Chop parsley (and dill or basil if using).
Toss the base: In a large bowl, combine warm pasta with half the dressing.
Add a splash of reserved pasta water if it seems dry. The warmth helps the pasta absorb flavor.
Add the good stuff: Fold in spinach, tomatoes, cucumber, bell pepper, red onion, olives, and feta. Add chicken and remaining dressing.
Toss gently to combine without smashing the feta.
Finish and taste: Sprinkle with parsley and a pinch of red pepper flakes if you like heat. Taste and adjust with more lemon, salt, or olive oil until it hits that bright, balanced spot.
Serve: Enjoy warm, at room temperature, or slightly chilled. It’s great as a bowl on its own or with warm pita on the side.