Clean the mushrooms with a damp paper towel and remove the stem. Slice them and set aside.
To a dish add flour, season with salt and pepper. Dip each piece of chicken into the flour mixture and set aside.
To a large sauté pan, add 1 tbsp of unsalted butter, garlic clove and 3 tbsp of olive oil.
Sear the chicken on both sides. It does not need to cook through at this time. Remove from the pan and set aside.
To the same pan, add another tbsp of butter and olive oil if needed. Add the mushrooms, sauté until tender and then season with salt and pepper.
Deglaze the pan with Marsala wine, cook for a few mins to cook out the alcohol and then add in 2 tbsp of butter rolled in the flour mixture you used to dredge the chicken. This will help thicken the sauce.
Once the butter has melted, add in the warm chicken broth.
Add the chicken back in and cook together for 5 mins, to finish cooking the chicken. This is also continue to thicken the sauce and the chicken will absorb all those flavors. Remove from the pan and place on a serving dish.
You can continue to cook the sauce to thicken or if you are satisfied with the thickness pour the sauce over the chicken and enjoy!