Season chicken thighs with salt and black pepper.

Place a large skillet over medium-high heat. Add in olive oil and sear the chicken thighs for 5-8 minutes on each side until cooked through. Remove the chicken from the skillet and set aside.

Now, add the butter into the skillet and let it heat up with all the chicken juices left inside the pan. Add in the onion and garlic and cook for about 1 minute.

Pour in chicken broth and reduce the heat to low. Now, add in the bacon and cook for 1-2 minutes.

Pour in the heavy cream and milk and stir all the ingredients inside the skillet. Add in the Italian seasoning, oregano, crushed chili pepper flakes, salt, and black pepper to taste.

Now, add the baby spinach and let it wilt. Add parmesan cheese and stir well.

Finally, combine cornstarch with water in a small bowl, and pour it into the skillet, mix it well quickly until the sauce thickens up.

Add the cooked chicken thigh back into the skillet, cover them with sauce and let them simmer until they heat up. Serve immediately with your favorite side dish.