1. Combine macaroni, tuna, peas, olives and onion in a large bowl; toss lightly; sprinkle with salt and seasoned pepper; toss again. Stir in soup until well blended; fold in cream cheese. Spoon mixture into an 8-cup baking dish; cover.
2. Bake in moderate oven (350°) for 30 minutes, or until bubbly-hot.