Step 1Melt the butter in a medium saute pan over medium heat. Add the shallots and cook until softened, 2 to 3 minutes. Add the mushrooms and cook, stirring often, 10 minutes.
Step 2Add the Cognac and cook until reduced to 2 to 3 tablespoons, about
Step 3Add the cream. Increase the heat and cook until the sauce thickens (the liquid should be reduced to one-half cup), about 2 minutes. Add the thyme and season with salt and pepper to taste. Keep the sauce warm while cooking the turkey.
Step 4Season the cutlets with salt and pepper on both sides. Heat 2 tablespoons olive oil in each of 2 large skillets over medium-high heat. Divide the sage between the pans and cook 1 minute, then push to sides of pans.
Step 5Lay cutlets in the pans and cook 2 minutes on a side, until just browned and cooked to taste. Drain the cutlets and sage on paper towels. Divide the cutlets among 4 plates, top each with a sage leaf and spoon the sauce over.