Step 1 Combine the flour and sugar in a food processor or mixer. With the machine running, slowly add the butter, and process or mix until you have a fine meal. Mix together the yolks and the cream, and slowly add it into the flour mixture. Process until the dough just starts to come together.
Step 2 Turn the dough onto a floured work surface; workwith the heel of your palm until it comes together flat and smooth. Form the dough into 8 small disks. Wrap in plastic wrap and refrigerate 2 hours.
Step 3Butter 8 (4-inch) tart pans. (If you only have 4 pans, you can make 4 shells at a time.) Roll the disks out to 1/8 inch thick. Form the dough into the tart pans. Use a rolling pan to roll over the tops of the pans until the excess dough drops from the sides. Press the dough gently to the sides of the pans. You must chill and weigh down the dough. The easiest way is by spraying a coffee filter with cooking spray and filling it with dried beans, then placing it on top of the pastry dough. Chill the shells for at least another 2 hours.
Step 4Heat the oven to 400 degrees.
Step 5Bake the shells (coffee-filter bags and beans still on top) until they become light amber, 15 to 20 minutes. Remove the coffee filters and let the shells cool to room temperature. Carefully remove the shells from the pans.