You may think, as writer Nancy Harmon Jenkins did for years, that pissaladière is just the Provençal name for onion pizza. Actually the word comes from pissala, a salted-fish concoction from Nice that's used as a savory topping for bread dough or pastry. This recipe is meant as a jumping-off point—let your own tastes dictate the toppings. More Pizza Recipes
The dough and the onion topping can be refrigerated separately overnight. Let both come to room temperature before assembling the tarts.
Salt-packed anchovies are available at Greek and Italian markets, and their flavor and texture are worth the extra fuss. Rinse under running water, then separate each into 2 fillets, discarding the spine and any fins or tail pieces.