The sauce is a zesty complement to the tart’s rich chocolate filling.
- 6 tbsp. butter
- ¼ c. granulated sugar
- 1¼ c. cake flour (not self-rising)
- 1 egg
- 1 c. heavy cream
- ⅓ c. whole milk
- ½ c. finely shredded basil leaves
- 8 oz. bittersweet chocolate
- 1 egg
- confectioners’ sugar
- Fresh basil sprig
- 3 pink grapefruits
- 3 tbsp. honey
- 1½ tsp. cornstarch mixed with 2 tsp. water
- To make tart shell: In the bowl of an electric mixer fitted with a paddle attachment, beat butter and granulated sugar until light and fluffy. With mixer on low speed, add flour and egg in two parts and beat just until combined. Shape dough into a disc, wrap in waxed paper, and chill 1 to 24 hours. Roll out dough on a lightly floured surface with a lightly floured rolling pin to 1/8- to 1/4-inch thickness. Transfer to a 9-inch tart pan, press in sides and bottom, and trim any excess dough around edges. Preheat oven to 350 degrees. Cover dough with a large piece of foil and weigh down with uncooked rice or beans. Bake 20 minutes, remove foil and beans, and bake 10 minutes longer, or until light golden brown. Cool on a rack.
- To make filling, preheat oven to 375 degrees. In a medium saucepan over medium heat, bring cream, milk, and basil just to a boil. Remove pan from heat, cover, and steep 10 minutes.
- Place chocolate in a medium bowl. Pour cream mixture through a strainer over chocolate and whisk until smooth. Let cool 10 minutes, then whisk in egg.
- Pour chocolate into tart shell and bake 20 minutes, or until filling is just beginning to set.
- Remove to a wire rack and let cool completely. Dust with confectioners’ sugar and garnish with basil sprig.
- Meanwhile, to make sauce: Chop grapefruit segments into small pieces, saving juice. In a medium saucepan over medium heat, bring fruit, reserved juices, and honey to a boil. Add cornstarch mixture and boil 1 minute, or until slightly thickened. Remove from heat, transfer to a bowl, and let cool to room temperature. Serve with tart (or with lemon cake).