POACHED PEACHES: In a medium saucepan, combine sugar and 2 cups water. Bring to a simmer over medium-high, and cook, stirring occasionally, until sugar dissolved. Add lemon juice and peaches.
Simmer until peaches are tender when pierced with the tip of a knife, about 10 minutes.
Remove saucepan from heat, and let peaches cool in the poaching liquid. Usin a slotted spoon, remove peaches from poaching liquid, peel, discarding skins.
Slice peach halves into 6 wedges each. Transfer peaches and poaching liquid to a bowl. Cover; Refrigerate until chilled.
DIRECTIONS: Preheat oven to 375°F On a lightly floured surface, roll out dough 1/8-inch thick. using a 5-inch cutter, cut twelve rounds, re-rolling the dough as needed. Brush off excess flour, and gently fit rounds into 3 1/2 -inch tart pans with removable bottoms.
Trim edges with scissors, a paring knife or rolling pin. Place tart pans on baking sheet . Chill for 30 minutes.
Using a slotted spoon, remove peaches form poaching liquid. Reserve poaching liquid for another use. Arrange three peach wedges in each tart shell.
In medium bowl, whisk together egg and sugar until thick and pale yellow. Add the flour and salt and whisk until smooth. Whisk in the cream and cognac.
Spoon custard around peaches in tart shells. Sprinkle lightly with sugar.
Bake until the custard is puffed and golden, about 35 minutes. Transfer to a wire rack to cool. Serve at room temperature.