Delicous pasta bake

1 14-ounce canwhole Italian-style tomatoes, undrained

1/2 of a 6-ounce can (1/3 cup)Italian-style tomato paste

1/4 cuptomato juice

1/2 teaspoonsugar

1/2 teaspoondried oregano, crushed, or 2 teaspoons snipped fresh oregano

1/4 teaspoonblack pepper

1 poundlean ground beef

1/2 cupchopped onion (1 medium)

1/4 cupsliced pitted ripe olives

1/2 cupshredded reduced-fat mozzarella cheese (2 ounces)