Crust: Cut flour, butter and salt very quickly to resemble coarse cornmeal. Add egg yolk and 2 Tablespoons of water; mix until the dough just comes together. If too dry, add a little more cold water. This may also be made in a food processor using plastic or metal blade. Wrap the dough in plastic and chill for at least 2 hours or overnight. (This dough freezes well.)

Preheat oven to 375° F. Lightly butter the bottom and sides of a 9-inch tart pan with a removable bottom. On a lightly floured work surface, roll out the dough to a diameter of at least 10 inches. Roll the dough onto the rolling pin and transfer to the tart pan. Gently press the dough into the bottom and sides of the pan. Trim off excess and prick the dough with a fork. Line the dough with heavy foil and fill with dried beans to weight the dough down. Bake for 5 to 7 minutes or until the dough is partially cooked, but not brown. Carefully remove the foil and beans; continue to bake 3 to 4 minutes longer, until lightly browned; remove and set aside to cool.

Caramel Filling: In a heavy saucepan over medium heat, combine sugar, ½ cup of the cream, corn syrup and butter. Bring the mixture to a boil, stirring occasionally. Cook until it reaches 240º F on a candy thermometer (soft ball stage). Slowly, as it will bubble up, add the remaining ¾ cup of cream. Return the mixture to a boil and cook until it reaches 220º F. Remove from the heat and cool slightly. Arrange nuts evenly in the baked tart shell and pour over the warm caramel sauce. Cool and refrigerate until firm.

Chocolate Glaze: Place all ingredients in a double boiler; cook over medium low heat just until the chocolate melts. Remove from heat and whisk until smooth. Quickly pour chocolate glaze over top of chilled tart. Rotate and tilt tart to spread quickly. Chill again to firm the chocolate. Return tart to room temperature before serving. Yield: 6 to 8 servings.