Preheat oven to 350 degrees F.
Melt butter in saucepan over medium heat. Blend in flour to make a roux. Add half-and-half all at once, stirring constantly until thickened and smooth. Add Parmesan, sherry, Worcestershire sauce, garlic powder and salt and pepper. Temper egg yolks with 2 tablespoons of hot mixture and add back to the cheese sauce. Set aside. Mix artichoke hearts, shrimp, and mushrooms together. Put in baking dish and pour sauce over top. Sprinkle top with grated cheese and paprika. Bake for 30 to 35 minutes. Serve with crackers or tortilla chips.