In a chilled mixing bowl, combine the flour, sugar, salt, butter, and lard. Rub the flour and fat together with your fingertips until the mixture is flaky and the consistency of coarse bread crumbs. Drizzle half of the beaten egg over and toss until the dough comes together, adding the remaining egg if necessary to bind the dough. Gather the dough into a compact ball and refrigerate for at least 1 hour before rolling out.
Preheat the oven to 400 degrees. On a lightly floured surface, roll out the dough into a rectangle about 1/8 inch thick. With a cookie cutter or the rim of a glass, cut the dough into 3 1/2 inch rounds. Gather the scraps into a ball, re-roll them and cut more rounds. Repeat until you have used all the dough. Fit the dough rounds into ungreased 2 1/2 inch tart pans or the cups of a muffin pan, pressing them gently against the bottoms and sides to form deep molds. Place the pan in the freezer for 10 minutes to firm the dough. Place the tins on a baking sheet and bake for about 20 minutes, until the pastry is golden brown. Set the shells aside in their tins to cool.
Reduce the oven to 350 degrees. In the bowl of an electric mixer or with a handheld mixer, beat the cream cheese, farmers cheese, and sugar together until light and fluffy. Add the egg yolk, cinnamon, and salt and beat until smooth.
Spoon the filling into the tart shells, dividing it evenly, and filling up to within 1/4-inch of the top. Bake in the middle of the oven for 20 minutes, or until the filling is set and doesn't jiggle when shaken. Cool the tarts to room temperature and carefully slip them out of their tins. Serve, garnished with a few grape halves.
c.1997, M.S. Milliken & S. Feniger, all rights reserved