01 - Season both sides of the chicken breasts generously with salt, freshly ground black pepper, dried oregano, and dried basil.
02 - Heat olive oil in a large skillet over medium-high heat. Place the chicken breasts in the skillet and sear for 3 to 4 minutes per side until a golden-brown crust forms. Remove the chicken and set aside on a plate.
03 - In the same skillet, melt the butter over medium heat. Add the diced onion and sauté for 2 minutes until translucent. Stir in the minced garlic and cook for 30 seconds until fragrant.
04 - Add the halved cherry tomatoes to the skillet and cook for 3 to 4 minutes, stirring occasionally, until they begin to soften and release their juices.
05 - Pour in the dry white wine and chicken broth. Use a wooden spoon to scrape up any browned bits from the bottom of the pan. Bring the liquid to a gentle simmer.
06 - Return the seared chicken breasts to the skillet. Cover with a lid, reduce the heat to low, and simmer for 12 to 15 minutes until the chicken is cooked through and reaches an internal temperature of 165°F.
07 - Add the fresh spinach to the skillet and cook uncovered for 2 to 3 minutes until fully wilted. Taste the sauce and adjust seasoning with additional salt, pepper, or chili flakes as desired.
08 - Transfer each chicken breast to a plate and spoon the tomato-spinach pan sauce generously over the top. Serve alongside rice, pasta, or crusty bread.