Pastry: Cut butter into 8 pieces. In food processor, blend flour, sugar,
lemon zest, salt and butter until the consistency of meal. Pour
into a bowl. With a fork blend in egg until all dough is moistened
and starts to hold together. On floured surface, knead dough lightly
with fingertips until it forms a ball. Add a sprinkling of water,
if necessary. Wrap dough in plastic wrap and refrigerate 1 hour
or overnight. Roll out chilled dough between 2 pieces of floured
wax paper. Fit into a 9-inch tart pan. Trim dough even with edge.
Refrigerate until ready to bake.
Frangipani Filling: Cream butter in food processor or blender. Add almond paste in small
pieces alternately with beaten eggs. Process until smooth, scraping
sides often. Add zest, almond extract, and flour. Process until
blended. Heat oven to 350 degrees F. Set tart pan on baking sheet.
Spread Frangipani Filling in bottom pastry shell. Bake for 50 minutes
until filling is golden and set. Cool on rack.
Glazed Lemon Slices: Layer lemon slices in medium saucepan. Add enough water to cover.
Bring to boiling. Reduce heat; boil gently until lemon rinds are
tender, 25 to 30 minutes. Remove lemon slices with slotted spoon.
drain on paper towels. Reserve 1 cup cooking liquid in pan. Gradually
add 1 cup sugar, stirring over medium low heat until sugar dissolves.
Bring to rapid boil. Boil until mixture becomes a thick syrup. A
small spoonful of syrup should hold its shape when dropped onto
a cold saucer. Remove syrup from heat.
To serve, arrange lemon slices in circles on top of tart. Glaze
with some of the hot lemon syrup. Garnish with violets and sliced
almonds. Surround the tart with lemon geranium leaves.