Heat 1 tablespoon of olive oil in a large skillet over medium-high heat.
Add the thinly sliced chicken breasts to the skillet and cook until golden brown and cooked through, about 5-6 minutes per side. Remove the chicken from the skillet and set aside.
In the same skillet, add another tablespoon of olive oil if needed, then add the thinly sliced onion and minced garlic. Sauté until the onions are translucent and fragrant, about 2-3 minutes.
Add the sliced zucchinis to the skillet and cook until they are tender but still slightly crisp, about 4-5 minutes.
Return the cooked chicken to the skillet and sprinkle dried oregano, dried basil, salt, and pepper over the mixture. Stir well to combine and let cook for another 2-3 minutes to allow the flavors to meld.
Once everything is heated through and well combined, remove the skillet from heat.
Serve the Chicken Zucchini hot, garnished with grated Parmesan cheese if desired.