Chop onion and mince garlic. Heat oil in a large saucepan over medium-high.  Add onion and garlic; saute 3 minutes or until onion starts to brown.  Add tomatoes, broth, oregano, and pasta, in that order. Press with a spoon to submerge the pasta in liquid.  Bring to a boil.  Cover, reduce heat to medium-low, and cook 7 minutes or until pasta is almost done.

Uncover pan; stir in salt.  Add spinach in batches, stirring until the spinach wilts before adding more.  Remove pan from heat; let stand 5 minutes.  Divide pasta mixture among 4 plates; sprinkle evenly with cheese. Serve with chopped mango.