I. Very creamy, very cheesy.
Cook in a large pot of boiling salted water:
Drain and return to the pot. Add:
Stir until well blended. Add and stir well:
Set the pot over low heat and cook, stirring constantly, until the sauce is smooth and the pasta is steaming, about 10 minutes. The sauce should thicken noticeably. Increase the heat slightly if the sauce is still soupy after 5 minutes, but watch it very carefully. Do not overheat, or the sauce will curdle.
II. Prepare Baked Macaroni and Cheese, but do not preheat the oven or grease a baking dish. Stir all the cheese into the sauce at once. After the pasta is cooked, stir it into the sauce and serve without baking; sprinkle the bread crumbs on top, if desired.