Add the King Arthur, keto, wheat, flour, Parmesan cheese, and Garlic Plus seasoning into a dredging bowl and whisk together.
In a separate dredging bowl, whisk together the egg and mayonnaise.
Place each chicken breast between two pieces of plastic wrap and pound with a meat, tenderizer hammer until the chicken is thin and a consistent thickness all the way across.
Dredge each chicken breast in the egg mixture, followed by the flour mixture, ensuring each chicken breast is well coated with the flour mixture.
In a large skillet, heat the oil or butter until hot.
Add coated chicken breasts to the hot pan and sauté until well browned and reach an internal temperature of 170° F (about 5 mins per side).
Remove the chicken from the pan and set aside.
Add the sliced mushrooms and minced garlic to the pan and stir well removing all the bits from the bottom of the pan.
Cook the mushrooms for 2 to 4 minutes and then add the chicken broth.
Cook for another 3 to 5 minutes and then pour in the heavy cream.
Simmer the mushrooms and cream mixture for approximately five minutes, stirring frequently.
Return the cooked chicken to the pan and simmer for another 5 to 8 minutes.
Add salt and pepper to desired taste.
Serve hot.