The dough will keep, well wrapped in plastic wrap in the refrigerator for 1 week or in the freezer for 1 month. Thaw the dough in the refrigerator until ready to use.
The recipe for the caramel-walnut base yields more than needed for one tart, and can be stored in the refrigerator, tightly covered with plastic wrap, for several weeks. Jacques Torres likes to eat it on toast for breakfast!
Variations: This tart can also be made with peaches, apples, apricots, or figs. (Peel and core the apples.)