1. Preheat oven to 400.
2. Cook macaroni, uncovered in 6 quarts of rapidly boiling salted water for 8 - 12 minutes until al dente. Drain well.
3. Combine the milk and cream in a small saucepan and bring to a simmer over moderate heat.
4. While the milk warms, heat the butter in another saucepan over low heat for 1 minute until foaming. Add the flour and cook, stirring, for 3 minutes.
5. Pour the hot milk into the butter-flour mixture and cook, stirring with a wire whisk or wooden spoon for a few minutes, until thickened.
6. Add the cheese to the white sauce, about 1;:4 c. at a time, stirring until the cheese has melted and the sauce is smooth. Add the pepper and salt to taste.
7. Stir the tomatoes and sugar into the cheese sauce.
8. Combine the cooked macaroni with the sauce, and put into a butter 1-1/2 quart-baking dish.
9. Bake for 25-35 minutes, until the top is nicely browned.