To make crust, pour 3/4 cup water into large bowl. Sprinkle yeast over; stir to blend. Let stand 10 minutes to dissolve yeast. Add oil, salt, and herbs, then 1 1/2 cups flour. Stir until well blended (dough will be sticky). Turn dough out onto generously floured surface and knead until smooth and elastic, adding just enough flour to prevent dough from sticking, about 5 minutes (dough will be soft). Shape dough into ball; place in large oiled bowl and turn to coat. Cover bowl with kitchen towel. Let dough rise at cool room temperature until almost doubled, about 2 hours. Punch dough down; form into ball. Return to bowl; cover with towel and let rise until doubled, about 3 hours.

Preheat oven to 425 degrees F. Punch down dough. Form into ball; place on floured work surface. Cover with kitchen towel; let rest 30 minutes. Sprinkle rimless baking sheet with cornmeal. Roll out dough on floured surface to 13-inch round. Transfer to baking sheet.

Heat a splash of olive oil in a skillet over medium heat. Add onions and saute, stirring frequently, 10 to 12 minutes or until onions are caramel colored and soft. Remove from heat.

Bake crust for 5-7 minutes or until just set, pressing down any large bubbles that might form. Remove from oven and quickly brush crust with olive oil and top with onions, pear, prosciutto, and cheese.

Bake pizza until crust is crisp and cheese begins to brown, 15-18 minutes. Transfer pizza to board. Cut into wedges and serve immediately.