This rustic tart is a breeze to prepare with a few pantry staples. The dough, which comes together quickly in a food processor, is dual purpose. Pressed into a tart pan, it forms the bottom crust and, pinched into small bits and scattered onto the filling, bakes into a buttery streusel topping. A little cornmeal in the dough adds textural interest and subtly sweet corn flavor. Just about any type of fruit jam or preserves works well. We particularly like cherry preserves and seedless raspberry jam; marmalade is a great option, too. A little black pepper mixed into the preserves offers just a hint of savoriness that balances the sweetness.