Robiola Pizza with White Truffle Oil

In a small bowl stir together yeast, oil, sugar, and about 3 tablespoons water until smooth. Stir in remaining water. In large bowl of a standing electric mixer fitted with dough hook whisk together 2 1/2 cups all-purpose flour, cornmeal, whole-wheat flour, and salt. With mixer on low speed stir in yeast mixture and blend until mixture forms a dough. With mixer on medium speed knead dough, adding enough of remaining 1 cup flour as necessary to prevent dough from sticking, until smooth and elastic, about 5 minutes.

Put dough in an oiled deep bowl and turn to coat with oil.

Let dough rise, loosely covered with plastic wrap, in a warm place 1 hour, or until doubled in bulk, and punch down. Divide dough into 5 balls.

On a lightly floured surface roll out each ball of dough into a 9 1/2-inch round and stack, lightly floured, between sheets of parchment paper. Dough may be made 8 hours ahead and chilled, tightly wrapped in plastic wrap.

Preheat oven to 550° F

Cut mushrooms into 1/4-inch dice. Quarter zucchini lengthwise and cut off seed core.

Cut zucchini into 1/4-inch dice and in a bowl toss together with mushrooms, chives, and salt and pepper to taste.

Spread 1 cup Robiola on each round of dough, leaving a 1/2-inch border around the edge.

Sprinkle 1 tablespoon cornmeal on each of 2 baking sheets and transfer 1 pizza to each. Scatter about 2/3 cup mushroom mixture over each pizza and bake in batches in lower third of oven 10 to 12 minutes, or until crust is crisp and golden.

Transfer pizzas to plates and drizzle each with 1 tablespoon truffle oil. Top and bake remaining pizzas in same manner.