Pat the chicken dry, season it with salt, pepper, and half of the Italian seasoning, then heat one tablespoon of olive oil in a large skillet.
Add the chicken in a single layer and cook for 6–8 minutes, turning occasionally, until browned and cooked almost completely through.
Transfer the chicken to a plate, add the remaining oil to the skillet, and cook the zucchini for 4–5 minutes until lightly golden.
Add cherry tomatoes and garlic, then cook for another 2 minutes until the tomatoes begin to soften and release a little juice.
Return the chicken to the skillet, sprinkle in the remaining Italian seasoning, and toss everything together over medium heat.
Drizzle with lemon juice and cook for another 2–3 minutes until the chicken is fully cooked and the flavors have combined.
Finish with fresh parsley and serve directly from the skillet with rice, quinoa, or crusty bread if desired.