To make the soufflé sheet: Preheat the oven to 375°F. Line a 10-by-15-inch baking pan with parchment paper or waxed paper. Heavily butter and flour the paper.

In a medium saucepan, melt the butter over medium heat and blend in the flour; cook and stir for 2 minutes. Gradually whisk in the milk, blending with a wire whisk, and cook, stirring, until thickened. Remove from heat and stir in the salt, brandy or sherry, nutmeg, and egg yolks, one at a time. Mix in the cheese.

In a large bowl, beat the egg whites until foamy. Add the cream of tartar and beat until stiff, glossy peaks form. Fold one-fourth of the beaten egg whites into the yolk mixture. Fold this mixture into the remaining egg whites. Spread the batter evenly in the prepared pan.

Bake in the oven for 15 minutes, or until the soufflé is golden brown and the top springs back when touched lightly. Turn the pan upside down on a cloth towel. Remove the pan and peel off the paper.

To make the filling: Mix all the filling ingredients together and spread over the soufflé. Roll up jelly-roll fashion from a lengthwise side. Place on a serving platter and garnish with cherry tomatoes. Serve warm or chilled, cut into 1-inch-thick slices.