In 4 1/2- or 5-quart Dutch oven, cook pasta as directed on package. Drain; rinse well. Return to Dutch oven; cover to keep warm.
Meanwhile, in 12-inch skillet, heat oil over medium-high heat until hot. Add chicken; cook and stir 2 to 4 minutes or until chicken is beginning to brown. Stir in onions, mustard and garlic. Cook until garlic is softened. Stir in tomatoes until blended. Cook 2 to 3 minutes, stirring occasionally, until chicken is no longer pink in center. If necessary, drain off any liquid.
Add frozen broccoli with sauce chips; cook about 4 minutes, stirring occasionally, until sauce chips have melted. Stir in cream cheese spread. Add milk; cook about 2 minutes, stirring constantly, until well blended and thoroughly heated.
Gently stir broccoli mixture into cooked pasta to coat. Salt and pepper to taste. Pour into serving bowl.