Preparation / Directions:
Preheat oven to 350F. Lightly butter 9x13x2-inch glass baking dish. Cook macaroni in large saucepan of boiling salted water until just tender but still firm to bite. Drain pasta. Transfer to prepared dish. Mix in cubed cheese.
Whisk flour, salt, mustard, black pepper, cayenne pepper and nutmeg in medium bowl until no lumps remain. Gradually whisk in half and half, then whipping cream and sour cream. Add eggs and Worcestershire sauce; whisk to blend. Pour over macaroni mixture; stir to blend. Sprinkle grated cheese over.
Bake macaroni and cheese until just set around edges but sauce is still liquid in center, about 25 minutes. Remove from oven; let stand 10 mins to thicken slightly (sauce will be creamy).