1/4 cup simple syrup, divided use (in a small covered saucepan, simmer 1/4 cup sugar and 1/4 cup water for 4 minutes to dissolve crystals)
6 tablespoons (3/4 stick) unsalted butter, melted
12 ounces dark Belgian chocolate
1 1/2 cups heavy cream
2 tablespoons Grand Marnier
zest of 2 large oranges, to candy for garnish
PREPARATION
Toast walnuts in a 350ºF oven for 5 to 10 minutes.
In a food processor coarsely chop 3 cups walnuts for crust.
Place chopped walnuts in a bowl, add 2 tablespoons of the simple syrup and the melted butter, mix well.
Place mixture in a 10 inch fluted tart pan with removable bottom and press into pan with your fingers to form a crust. Put pan in freezer to firm while you complete the next step (about 10 minutes).
Use a knife to break chocolate into small shards.
In a medium saucepan bring cream to a boil, add chocolate and remove from heat. Stir until smooth. Stir in Grand Marnier.
Pour mixture into chilled tart mold and refrigerate for 4 hours or overnight.
In a small nonstick sauté pan, combine the remaining 2 tablespoons simple syrup and the orange zest. Cook over medium heat until most of the water has evaporated and the zest is translucent, 2 to 3 minutes. Remove from pan and cool.
To serve, keep chilled until ready to serve. Remove tart from pan. To slice, use a knife dipped in hot water and wiped with a towel. Cut into 12 slices. Garnish slices with powdered sugar-dusted walnut halves and candied orange zest.
