1. Heat oven to 400 degrees F. Cut top off head of garlic; remove loose skin. Brush cut end of garlic head with 1 tablespoon of the olive oil. Wrap head in aluminum foil.
2. Roast garlic in 400 degree oven for 50 minutes or until garlic is softened. Let cool. (This can be done ahead and refrigerated.)
3. Place the 1 cup warm water (110 degrees F to 115 degrees F) in glass measure. Sprinkle yeast over the water; let stand until foamy, about 5 minutes. Then stir to dissolve yeast.
4. Meanwhile, squeeze garlic pulp from cloves into small bowl.
5. Whisk together flour, rosemary, salt, and sugar in large bowl. Make well in center. Slowly pour yeast mixture, roasted garlic pulp and the remaining 2 tablespoons olive oil into the well; mix the liquid into the flour mixture with a wooden spoon until dough comes together. Turn dough out onto well-floured surface. Knead for 10 minutes or until the dough is smooth and elastic.
6. Place the dough in an oiled bowl; turn the dough to coat with the oil. Cover with clean kitchen towel; let rise in warm place for about 1-1/2 hours or until doubled in volume.Topping:
7. While dough is rising, heat oil in large skillet over medium heat. Add onions; cook, stirring occasionally, for 20 minutes or until nicely browned. Add rosemary and salt. (The topping can be prepared ahead, and refrigerated, covered.)
8. When dough has risen, punch down. Sprinkle cornmeal over 15 x 10 x 1-inch jelly-roll pan. Firmly stretch dough to fit pan. With fingers, make dimples over dough. Spread with onion mixture. Cover with towel; let rise in warm place 45 minutes, until doubled in volume.
9. Heat oven to 400 degrees F. Sprinkle cheese over top of dough.
10. . Bake focaccia in 400 degree oven for 25 minutes or until the crust is browned and the cheese is bubbly. Cut into 12 pieces. Makes 12 servings. Bread Machine Method In bread machine, place the 2 tablespoons olive oil, roasted garlic pulp and remaining dough ingredients in the order specified in the manual for your bread machine. Let bread machine run on dough cycle following the directions in your manual. While the machine is running, prepare the Topping in step 7, above. When dough cycle is completed, remove dough from machine. Proceed with step 8, above, stretching the dough into the prepared pan.