In a wide frying pan or chafing dish over high heat on a range, melt butter until it is lightly browned. Add 1/2 cup of the cream and tomatoes and boil rapidly until large shiny bubbles form; stir occasionally. (You can make this part of the sauce earlier in the day, then reheat.) Reduce heat to medium or place chafing dish over direct flame. Add noodles to the sauce. Toss vigorously with 2 forks, and pour in the cheese and the remaining cream, a little at a time--about three additions. The noodles should be kept moist but not too liquid. Season with salt and pepper and grate nutmeg generously over the noodles (or use about 1/8 teaspoon of the ground spice.) Serve immediately.