Prepare your ingredients by chopping chicken breasts into bite-sized chunks, slicing zucchini, red bell peppers, and red onion, and halving cherry tomatoes. Mince garlic finely.

Heat 2 tablespoons of olive oil in a large skillet over medium-high heat. Season chicken with salt and pepper, add to the pan, and sear for about 6-8 minutes until cooked through. Set aside.

In the same skillet, add remaining oil and reduce heat to medium. Sauté red onion and minced garlic for 2 minutes until fragrant.

Add sliced zucchini, red bell peppers, and cherry tomatoes. Stir-fry for 4-5 minutes until vegetables are just tender.

Return chicken to the skillet. Mix in sun-dried tomatoes, dried herbs, lemon juice, and olives. Adjust salt and pepper to taste.

Sprinkle feta cheese over the top before serving. Garnish with fresh parsley if desired.