Cook rotini as directed on package. Drain well.
Meanwhile, in 2 1/2-quart saucepan, cook ground beef, zucchini and oregano over medium-high heat for 5 to 7 minutes or until thoroughly cooked, stirring frequently. Drain.
Stir in flour and salt. Add milk, chicken broth, cheese sauce and cooked rotini to ground beef mixture; mix gently. Simmer about 5 minutes or until cheese is melted, stirring occasionally.