Grapefruit and Banana Rum Gratins

Preparation

1. Step 1

   Divide the grapefruit sections and the banana slices among four 6-inch (1- to 1 1/4-cup-capacity) gratin dishes. In a small saucepan combine the milk and the vanilla bean and bring the milk just to a boil. While the milk is heating, in a metal bowl whisk together the whole egg, the egg yolk, the granulated sugar, the flour, sifted, and a pinch of salt. Add the milk mixture in a stream, whisking. Transfer the pastry cream to the pan, bring it to a boil, and simmer it, whisking, for 2 minutes.

   Step 2

   Force the pastry cream through a fine sieve into a bowl, discarding the vanilla bean, whisk in the rum, and let the pastry cream cool slightly. In another bowl with an electric mixer beat the heavy cream until it holds stiff peaks, whisk a small amount of the whipped cream into the pastry cream, and fold in the remaining whipped cream gently but thoroughly. Pour one forth of the cream mixture into each gratin dish, spreading it to cover the fruit completely, and sprinkle each gratin with some of the confectioners' sugar. Arrange the gratins in a large baking pan and broil them under a preheated broiler about 4 inches from the heat for 2 to 4 minutes, or until they are browned and heated through.