Sautéed Mushrooms with Sherry & Shallots

Heat oil in a large skillet over medium-high heat. Add shallots and cook, stirring, until softened, about 3 minutes. Add mushrooms, rosemary, salt and pepper; cook, stirring, until the vegetables are cooked through and starting to brown, about 8 minutes. Add sherry; continue cooking until the sherry is mostly evaporated, 1 to 2 minutes more. Sprinkle with Parmesan, if desired.