Once the turkey or pheasant breast has been pounded, salt it well and set aside until it comes to room temperature, about 15 minutes.
In a large saute pan, heat the butter and olive oil over medium-high heat until the butter froths. Add the smashed garlic and turn the heat to medium-low. Meanwhile, dredge the turkey in flour.
By now the garlic should be browned. Do not let it burn! Remove it and add the turkey or pheasant cutlets. Turn the heat to medium and fry gently. Don't kick the spurs to it, or the breading will burn. After 2-3 minutes, depending on how thin you pounded the cutlets, flip and cook another 1-2 minutes.
When the meat is cooked, remove it to a paper towel. Turn the heat to high and add the mushrooms. Saute these until they begin to brown, about 4-5 minutes. Add the Marsala, rosemary and the stock. If there are any burned bits on the bottom of the pan, scrape them up with a wooden spoon. Let this boil down until it gets syrupy, which should take 2-4 minutes. As soon as it gets syrupy, put the cutlets back in the pan and swirl around to coat. Turn over and do the same on the other side. Serve at once.