Cook Pasta In Boiling Water Until Done. Drain. Melt Butter Over Medium Heat In A Large Saucepan. Saute Onions, Mushrooms, And Garlic Until Tender. Stir In Sun-Dried Tomatoes, Olives, Artichoke Hearts, Wine, And Lemon Juice. Bring To A Boil; Cook Until Liquid Is Reduced By A Third, About 4 Minutes. Toss Pasta With Sauce. Top With Tomatoes And Cheese, Add Pepper To Taste, And Serve.