Preheat the oven to 425°F. In a small bowl, whisk together the olive oil, lemon juice, garlic, oregano, thyme, Dijon mustard, salt, and pepper.
Place the chicken thighs in a bowl and pour two-thirds of the marinade on top. Toss with your hands until well coated, then marinate for 10 to 15 minutes.
While the chicken marinates, spread the zucchini, bell pepper, red onion, and tomatoes onto the baking sheet. Drizzle the remaining marinade over the vegetables and toss to coat.
Nestle the chicken thighs among the vegetables on the baking sheet and bake for 30 minutes.
Remove the pan from the oven, sprinkle the olives and feta on top, then return to the oven for another 10 to 15 minutes, or until the vegetables are softened and the chicken reaches 165°F internally.
Sprinkle with fresh chopped parsley before serving.
Notes
Store leftovers in an airtight container in the fridge for 3 to 4 days, or freeze for up to 3 months. Reheat in the microwave for 2 to 3 minutes, or air fry at 375°F for 5 to 8 minutes to re-crisp the skin. Boneless, skinless thighs can be used but will cook faster. Chicken breasts can be substituted if vegetables are roasted alone first, adding the breasts in for the last 25 minutes.