Place both loaves of dough seam side down on a greased 14-in. pizza pan, forming one large ring; pinch ends to seal. With a sharp knife, make eight 1/2-in.-deep slashes across the top of dough; lightly brush with oil.
Spread garlic over oil; sprinkle with Italian seasoning. Bake at 350° for 25-30 minutes or until golden brown. Cool for 10 minutes before removing from pan to a wire rack to cool completely.
To assemble, cut bread in half horizontally. Brush salad dressing over cut sides. Layer the bottom half with ham, cheese, beef, lettuce, onion, green pepper and tomato; replace top. Serve immediately.