Press refrigerated piecrust on bottom and up sides of a square 9-inch tart pan. Bake at 450° for 9 minutes or until piecrust is lightly browned; set aside.
Cut off pointed end of garlic bulb; place garlic on a piece of aluminum foil, and drizzle with olive oil. Fold foil to seal.
Bake garlic at 425° for 30 minutes; cool. Squeeze pulp from garlic cloves into bottom of baked piecrust.
Sprinkle 1/2 cup fontina cheese over the garlic.
Slice tomatoes, and sprinkle evenly with salt and pepper. Place on folded paper towels, and let stand 10 minutes. Arrange tomato slices over shredded cheese. Sprinkle with remaining 1 cup cheese.
Bake at 350° for 45 minutes or until tart is lightly browned.