-
1
Set aside 200 grams oranges and 1 grapefruit.
-
2
Slice the ends off the remaining oranges and grapefruit and remove the peel and white pith by slicing down the sides from top to bottom.
-
3
Holding the fruit over a bowl, cut the sections from between the membranes that separate them.
-
4
Place a strainer over a bowl and drain the fruit.
-
5
Arrange the sectioned fruit in a lightly buttered baking dish or in 6 oven-proof creme brulee dishes.
-
6
Sprinkle the fruit lightly with cinnamon.
-
7
Pour the strained juice from the fruit into a measuring cup.
-
8
Squeeze the remaining grapefruit and enough of the remaining oranges to obtain 200 grams of juice (about 3/4 cup).
-
9
Pour the juice into a medium saucepan and add half the sugar.
-
10
Cut the vanilla bean in half lengthwise and using the tip of a knife, scrape the seeds into the juice.
-
11
Add the vanilla bean pod to the juice.
-
12
Bring to a simmer and immediately turn off the heat, cover the pan tightly with plastic wrap, and allow the vanilla bean to steep for 15 minutes.
-
13
Remove the plastic wrap.
-
14
Fill a bowl with ice and set another bowl in it.
-
15
Place a strainer over the bowl.
-
16
Beat the egg yolks with the remaining sugar in a small bowl and bring the juice back to a simmer.
-
17
Remove from the heat and, making sure that the juice isnt boiling, whisk half of it into the egg yolks.
-
18
Whisk the tempered egg yolks into the saucepan, scraping out every last bit from the bowl with a rubber spatula.
-
19
Place the saucepan back over medium-low heat and heat, stirring constantly with a rubber spatula or a whisk.
-
20
Do not allow the liquid to come to a boil.
-
21
Insert a thermometer and when the mixture reaches 180 degrees Farenheit and coats the spatula like thick cream, remove from the heat and immediately strain into the bowl set in the ice.
-
22
Whisk in the creme fraiche and stir over the ice until the mixture cools.
-
23
At this point, if you are not serving the gratin right away, cover and refrigerate the custard sauce.
-
24
Preheat the broiler and place the rack about 3 inches away from the heat.
-
25
Spoon the custard over the fruit.
-
26
Just before serving place under the broiler and, watching closely, heat until the cream is lightly browned, 3 to 5 minutes.
-
27
Remove from the heat and serve.
