Steps
1. Preheat the oven to 180°C (350°F).
2. Heat olive oil in a pan over medium heat. Add garlic and sauté until fragrant.
3. Add mushrooms and cook until soft, about 4 minutes.
4. Stir in chopped spinach and cook until wilted, about 2 minutes. Remove from heat.
5. Mix the sautéed vegetables with cream cheese, salt, and pepper.
6. Cut a pocket into the side of the chicken breast without cutting all the way through.
7. Stuff the chicken breast with the spinach and mushroom mixture.
8. Secure with toothpicks if necessary and season the outside with salt and pepper.
9. Place the stuffed chicken breast in an oven-safe dish and bake for 25-30 minutes, until the chicken is cooked through.
10. Let rest for 5 minutes before serving.