01 - Pat the chicken breasts dry and season both sides generously with salt, freshly ground black pepper, dried oregano, and dried basil.
02 - Heat olive oil in a large skillet over medium-high heat. Add the seasoned chicken breasts and cook for 5–6 minutes per side until golden brown and cooked through to an internal temperature of 165°F. Remove from the skillet and set aside on a plate.
03 - In the same skillet, add the finely chopped onion and sauté for 3 minutes until softened and translucent. Add the minced garlic and cook for 1 additional minute until fragrant.
04 - Add the halved cherry tomatoes to the skillet and sauté for 3–4 minutes until they begin to soften and release their juices. Pour in the chicken broth and bring the mixture to a gentle simmer.
05 - Stir in the roughly chopped spinach and cook for approximately 2 minutes, tossing gently, until just wilted.
06 - Return the seared chicken breasts to the skillet, nestling them into the tomato-spinach mixture. Simmer together for 2–3 minutes to heat the chicken through and allow the flavors to meld.
07 - Transfer to serving plates and sprinkle with grated Parmesan cheese if desired. Serve immediately alongside rice, pasta, or cauliflower rice.