Make the dough:
Pour the water into a large bowl. Sprinkle in the yeast and sugar, and stir to dissolve. Let it stand until the mixture begins to bubble. This should take about 5 minutes. If the mixture doesn't bubble, start it over with another packet of yeast.
Stir in 1 cup of flour, the salt, and 1 tablespoon olive oil. Mix with a wooden spoon until thoroughly incorporated. Add the remaining flour 1/2 cup at a time, mixing after each addition.
On a lightly floured surface knead dough until smooth and elastic, about 10 minutes. Oil a large bowl with the remaining olive oil. Place dough in oiled bowl, cover with plastic wrap and a warm dish towel, and let the dough rise in a warm place until doubled in bulk. This will take 1 to 1 1/2 hours.
Punch down the dough, and return it to the floured surface. Divide dough into two balls and cover each with plastic wrap, leaving room for expansion. Allow to double in size again.
Caramelized Onions: Heat oil in large nonstick saute pan over medium heat. Add thinly sliced onions and season with salt; saute 5 minutes. Reduce heat to medium-low. Stir frequently to get an even color. Cook until very tender and a rich golden color develops, about 20 minutes longer. Cool slightly.
Preheat oven to 475 degrees. Roll out 2 dough disks on lightly floured surface to 8-inch rounds. Sprinkle two baking sheets or pizza stones with cornmeal. Rub a generous drizzle of olive oil on dough. Rub raw garlic clove all over dough. Top with fontina, caramelized onions, and pancetta. Season with salt and pepper.
Bake pizza for 10-12 minutes, until bubbling and crisp.