Season the chicken with salt and pepper. Place the flour, garlic powder, onion powder, paprika, and cayenne in a shallow bowl. Dredge the chicken through the flour and toss to coat.
Arrange the prosciutto in a large skillet set over medium-high heat. Cook until crispy all over, about 5 minutes. Remove from the skillet.
In the same skillet, add 1 tablespoon butter and the chicken. Sear on both sides until golden, 3-5 minutes per side. Add 1 tablespoon butter and allow the butter to brown around the chicken, about 2 minutes. Remove the chicken from the skillet.
Add the mushrooms. Cook undisturbed for 5 minutes or until golden. Add 2 tablespoons butter, the shallots, thyme, sage, and a pinch each of salt and pepper. Cook for 5 minutes, until the mushrooms have caramelized.
Add the wine, then the broth. Simmer for 5 minutes, pour in the cream. Add the chicken to the skillet. If the sauce is too soupy, add 1-2 additional tablespoons flour. Sprinkle over the Gruyère. Cook for 5-10 minutes, until the cheese is melted. Remove from the heat. Top with crispy prosciutto and fresh herbs.
Serve the chicken with crusty bread for mopping up all that delicious creamy sauce.
