Zest-First Dry Brine: In a large bowl, combine the lemon zest, half the garlic, oregano, thyme, smoked paprika, pepper, and half the salt. Add the chicken thighs, toss to coat thoroughly, and let stand 10–15 minutes.
Bright Marinade: In a small bowl, whisk the lemon juice, Dijon, extra-virgin olive oil, and the remaining garlic and salt until emulsified.
Gloss the Vegetables: On a parchment-lined sheet pan, toss zucchini, bell pepper, red onion, tomatoes, and chickpeas with 2–3 tablespoons of the marinade (just enough to lightly coat). Spread into an even layer.
Stage the Pan: Nestle the chicken thighs on top of the vegetables, presentation side up, spacing them evenly.
Roast & Render: Roast at 425°F (220°C) for 24 minutes, until the vegetables begin to soften and the chicken edges look opaque.
Olives In, Baste & Continue: Scatter the olives over the pan. Spoon 1–2 tablespoons of the remaining marinade over the chicken and a few hot spots on the pan. Continue roasting 14 minutes more, until the chicken reaches 165°F (74°C) at the thickest part (avoid the bone). Discard any unused marinade after basting.
Optional Color Boost: Broil for 1–2 minutes to deepen golden edges.
Finish & Serve: Remove from the oven, sprinkle with parsley and a light crumble of reduced-fat feta (if using). Spoon a little pan jus over each portion.