In a large skillet, heat the olive oil over medium-high heat. Season the chicken breasts with salt and pepper on both sides. Add the chicken to the skillet and cook for about 6-7 minutes on each side, or until golden brown and cooked through. Remove the chicken from the skillet and set aside.
In the same skillet, add the minced garlic and sauté for about 30 seconds until fragrant. Add the cherry tomatoes and cook for 2-3 minutes until they start to soften.
Stir in the fresh spinach and cook until wilted, about 1-2 minutes.
Reduce the heat to medium-low and pour in the heavy cream. Stir in the Parmesan cheese, Italian seasoning, and red pepper flakes (if using). Allow the sauce to simmer for 3-4 minutes until it thickens slightly.
Return the chicken to the skillet, spooning the sauce over the top. Cook for an additional 2-3 minutes to heat the chicken through.
Garnish with fresh basil before serving.