I stumbled on this combination of flavors while working on an entirely different dessert recipe for a restaurant where I have a sometime internship doing pastry work. I was testing out making individual buttermilk pudding cakes, and needed something somewhat seasonal to top them with. Citrus seemed like the obvious choice, and while searching for a recipe for some sort of citrus salad, I came across one for citrus in star anise syrup. I tried it out with the cakes and fell in love with the pairing. That same night I came home to find the newly posted theme to this week’s contest, and knew I wanted to revisit the combination.
The crust is my favorite pastry crust recipe. Not only does it have a wonderfully crisp texture and rich brown butter flavor, it is also essentially foolproof: no worrying about cold butter or overmixing, no chilling or rolling, no need even for pie weights. I adapted the filling from a classic recipe for buttermilk pie, reducing it slightly to make for a more delicate tart, and using brown sugar instead of white for a hint of caramel flavor. Finally, the bruleed citrus topping was inspired by one of my favorite things for a late winter morning: a grapefruit half, generously sprinkled with brown sugar and broiled.
The custard in this tart is rich and comforting, while the star anise gives a touch of spiced warmth to the tart brightness of the citrus. The combination makes this tart just the thing for that last dreary stretch of winter before the spring thaw.
Using a spatula, mix together the melted butter and sugar in a medium bowl.
Add the flour and salt and stir until the dough comes together and the flour is entirely incorporated.
Transfer the dough to a 9" springform pan and press it evenly into the pan with your fingertips, pushing up the sides to be about 1.5 inches high. Prick the bottom of the crust all over with a fork.
Bake the crust until it is golden, for about 18 minutes. Remove from oven and set aside to cool in pan.
Reduce the oven temperature to 350 F. Prepare the buttermilk custard while the crust is cooling.
Buttermilk Filling and Citrus Topping
For the buttermilk custard: Add buttermilk, eggs, yolk, butter, 2/3 cup brown sugar, flour and salt to food processor. Process until combined and the mixture is smooth.
Pour custard into tart shell and bake at 350 F for about 35-40 minutes, until the filling puffs and the center is almost set, but jiggles slightly when shaken gently.
Set the tart aside to cool while you prepare the citrus topping.
For the citrus brulee: Cut away the pith and skin from the grapefruit and the blood oranges, leaving the flesh exposed. Slice the fruit along its width into circular slices 1/8" thick. If necessary, remove any seeds or inner white pith. Gently pat the citrus slices dry with a paper towel to remove any excess juice.
Arrange the citrus slices in an alternating pattern over the top of the tart.
Grind the star anise in a spice grinder (or with a mortar and pestle) until finely ground. Add the 1/4 cup of brown sugar and grind for 5-10 more seconds, until well blended.
Sprinkle the sugar mixture over the citrus and melt the sugar by using a blowtorch, or by placing the tart under the broiler for 2-3 minutes.