You will love the flavorful, buttery crust and light sabayon filling of this mixed citrus sabayon tart. Think of it as a rich bar cookie made in tart form--the filling and the crust are about the same thickness, and it's the play of contrasts that make these so very tasty!
Put all the ingredients into the bowl of your food processor and process until you get a crumbly dough. This will take awhile. You will think it's never going to happen, until it does. So be patient.
Form the dough into a disc, wrap in plastic wrap, and refrigerate for half an hour.
Roll the dough out to a thickness of 1/4". Line a 9" or 10" tart pan with the dough. If the dough tears, don't worry, just patch it all back together, and press to seal.
Work the dough up the sides of the pan, making sure to press it into the corners of the pan.
Roll across the top with a rolling pin, and remove excess dough.
Freeze the crust for 30 minutes.
Bake at 350F for 25 minutes, or until the crust is golden. Allow to cool before filling with the filling. Leave the oven on.
For the Curd
Place the butter in a bowl, and put a fine-mesh strainer in the bowl. Set aside.
Place all the rest of the ingredients into a heavy-bottomed saucepan.
Whisk constantly and quickly over medium heat until the mixture is very light in color, very thick, and about doubled in volume. This will take a few minutes, but when it finally happens, it will happen quickly.
Immediately remove the filling from the heat and pour through the strainer.
Press all of the mixture through the strainer with a silicone spatula.
Stir to incorporate the butter.
To Assemble
Pour the filling into the tart shell, and fill it all the way to the top. You'll have some filling leftover, so be thinking of a fabulous way to use it up.
Bake at 350F for ten minutes.
Remove to a cooling rack to cool, and then refrigerate.
Notes
Use any kind of tangy fruit you want for the curd; you just want a total of 6 ounces.Be sure to freeze the crust before baking. This will help it hold its shape while baking.Ideas for using up the extra filling: spoon over ice cream or cake. Dip fruit into it. Eat it with a spoon. Put in a pretty jar and give it to a neighbor.