In a large skillet, cook chicken in oil over medium-high heat until no longer pink.
Set aside the cheese packet from the macaroni dinner mix. Stir in the pasta, broth, zucchini, onion and oregano. Bring to a boil. Reduce heat; cover and simmer for 7-8 minutes or until pasta is tender, stirring occasionally.
Stir in tomatoes and the contents of the reserved cheese packet. Cook and stir for 3-4 minutes or until heated through.