Rinse the chicken breasts and pat them dry using paper towels.
Pound the chicken using a meat tenderizer or a rolling pin until they are thin and even in thickness.
Heat olive oil in a large skillet over medium-high heat.
Once the oil is hot, arrange the chicken breast in the pan in a single layer.
Cook for 5-8 minutes on each side until nicely browned on the outside and cooked through. Transfer to a plate and cover to keep warm.
Add garlic and mushrooms to the same pan and saute over medium heat till the garlic is fragrant and the mushrooms are tender about 3-4 minutes, stirring frequently.
Add basil pesto to the pan and saute for 1-2 minutes.
Now add chicken broth and stir to combine with pesto.
Add heavy cream and cream cheese and continue to stir until the sauce is smooth.
Now add milk and parmesan cheese and stir until the cheese is melted and combined with the sauce.
Check for salt and pepper and add as required.
Transfer the chicken to serving plates and pour the hot sauce on top.
Garnish with grated parmesan cheese and fresh basil leaves and serve hot.