This tart is a wonderful dessert for parties or entertaining, as it can be made and chilled up to two days ahead of time.

Makes a 9 or 10 inch tart, serves 10-12

To make the crust, mix the flour, sugar, salt and lemon peel in a food processor. Add the butter, followed by the egg yolk and vanilla. Process the dough it begins to hold together in clumps. Gather the dough and flatten into a disk and wrap in plastic wrap. Chill for at least 20 minutes. (You can also make the dough by hand by cutting th butter then mixing in the remaining ingredients, but a food processor makes it easy.)

Preheat oven to 400° F. Roll out dough and fit in a 9 or 10 inch tart pan. Pierce the surface of the crust all over with a fork to keep it from bubbly up during baking. Place tart pan with dough in the freezer for 10 minutes, then bake for 15-20 minutes or until crust is golden brown. Cool on a wire rack.

To make chocolate filling, place cream in a heavy saucepan and bring to a boil. Remove from heat and stir in the chocolate. Continue stirring until chocolate is completely melted and mixture is smooth. Spread 1 1/4 cup of the chocolate filling inn the bottom of the tart crust.

NOTE: If you plan on topping your tart with chopped nuts, then put all the chocolate mixture in the baked tart crust. If you're not using nuts, reserve the remaining chocolate for the top layer decoration. Chill the tart crust filled with chocolate for about 30 minutes.

To make the caramel