-
1
Bring 2 cups milk with salt to a boil in a 3-quart heavy saucepan.
-
2
Meanwhile, whisk together yolks, sugar, flour, cornstarch, and remaining 1/4 cup milk in a bowl.
-
3
Add one third of hot milk to yolk mixture in a slow stream, whisking, then add to milk remaining in saucepan, whisking.
-
4
Bring custard to a boil over moderate heat, whisking, and boil, whisking, 2 minutes.
-
5
Remove from heat and stir in butter until melted, then stir in grappa.
-
6
Transfer custard to a bowl and chill, its surface covered with wax paper, until cold, at least 1 hour.
-
7
Simmer rhubarb, water, sugar, and grappa in cleaned 3-quart heavy saucepan, uncovered, stirring gently once or twice, until rhubarb is tender but not falling apart, about 4 minutes.
-
8
Set pan in a bowl of ice and cold water and let stand 2 minutes to stop cooking.
-
9
Slowly pour rhubarb mixture into a sieve set over a bowl.
-
10
Return syrup to saucepan, reserving rhubarb, and boil until reduced to about 1/2 cup, about 10 minutes.
-
11
Keep rhubarb and syrup, covered, at room temperature until ready to use.
-
12
Preheat oven to 400F.
-
13
Unfold 1 puff pastry sheet and gently roll out into a 14-inch square with a rolling pin on a lightly floured surface.
-
14
Transfer to a buttered large baking sheet and prick all over with a fork.
-
15
Repeat with remaining sheet.
-
16
Bake in upper and lower thirds of oven, switching position of sheets halfway through baking, until pastry is puffed and golden, about 15 minutes total.
-
17
Cool on baking sheets on racks.
-
18
Trim edges of pastry with a large serrated knife.
-
19
Cut each sheet into 12 (3-inch) squares and break pastry scraps into small shards.
-
20
Beat cream (for custard) in a bowl with an electric mixer until it just holds soft peaks.
-
21
Whisk custard to loosen, then fold in whipped cream gently but thoroughly.
-
22
Dollop 2 rounded tablespoons of grappa cream on each of 8 dessert plates and top with half of rhubarb.
-
23
Cover cream and rhubarb on each plate with a pastry square.
-
24
Make another layer with remaining grappa cream, rhubarb, and pastry squares, then top with pastry shards.
-
25
Sift confectioners sugar evenly over each serving and drizzle with syrup.
