Place potatoes in a saucepan; cover with water. Bring to a boil. Cook 10 minutes or until just tender; drain. Cool slightly; cut potatoes crosswise into 1/4-inch slices.
Heat olive oil in a large nonstick skillet over medium-high heat.
Add onion to pan, and saut 8 minutes or until tender.
Roll dough out on a lightly floured surface to a 14 x 10inch rectangle.
Sprinkle cornmeal over a large baking sheet; place dough on baking sheet.
Sprinkle mozzarella evenly over dough. Arrange potatoes and onion over mozzarella; top evenly with goat cheese and garlic.
Bake in lower third of oven at 450 for 15 minutes or until browned.