In 12-inch nonstick skillet, cook chicken and onion over medium-high heat, stirring constantly, until onion is tender and chicken just begins to brown.
Stir in soup, mustard and dill weed. Heat to boiling. Stir in noodles; return to boiling. Reduce heat to medium; cover and cook 6 minutes, stirring occasionally.
Add broccoli; cook uncovered 3 to 4 minutes longer, stirring frequently, until broccoli is crisp-tender. Stir in cream cheese until well blended.