01 - Season both sides of the chicken breasts generously with salt, pepper, dried oregano, and dried basil.
02 - Heat olive oil in a large skillet over medium-high heat. Sear the chicken breasts for 3–4 minutes per side until a golden-brown crust forms. Remove and set aside on a plate.
03 - Melt butter in the same skillet. Sauté the diced onion for about 2 minutes until translucent, then add the minced garlic and cook for 30 seconds until fragrant.
04 - Add the halved cherry tomatoes and cook for 3–4 minutes, stirring occasionally, until they soften and release their natural juices.
05 - Pour in the dry white wine and chicken broth. Scrape the bottom of the skillet to release any browned bits, then bring the liquid to a gentle simmer.
06 - Return the seared chicken to the skillet. Cover with a lid, reduce heat to low, and simmer for 12–15 minutes until the chicken is cooked through to an internal temperature of 165°F.
07 - Stir in the fresh spinach and cook for 2–3 minutes until wilted. Taste the sauce and adjust seasoning with salt, pepper, and chili flakes if desired.
08 - Serve each chicken breast spooned with the tomato-spinach pan sauce, alongside rice, pasta, or crusty bread.