DOUGH (PATE SABLEE): In a food processor, combine butter, sugar, salt, vanilla and egg and pulse until blended. Pulse in the flour and almond meal just until the dough comes together. Pat dough flat into a disk on plastic film, wrap and chill at least 1 hour.
Cut dough into two pieces and roll out to about 1/8-inch thickness. Cut round pieces a little larger than the 4-inch mold. Ease each dough piece down into a mold and press dough along the bottom and edge. Flush excess dough off top edge of mold to keep the edge even. Complete placing the dough in remaining molds. Chill for at least 1 hour. Pre-heat oven to 400 F.
Line shells with wax paper and fill with raw rice or beans to weigh the dough down to blind bake the shells. Bake the shells until sides are light brown. Remove paper and beans from shells and let cool.
CITRON FILLING: In a food processor, pulse lemon sections just enough to slighty break up the sections. This should not be a smooth puree. Add remaining ingredients and pulse briefly just to mix together. Line pre-baked tart shells on a baking tray. Place filling in a large measuring cup with a spout or a pitcher and fill each tart shell all the way to the top. Bake in a 300 degrees F pre-heated oven for approximately 10 to 15 minutes, just until filling is set and no longer liquid. Serve room temperature with whipped cream and fresh berries.
Courtesy Kate Jansen, Willow Restaurant, Arlington, Virginia