Preheat oven to 325. In a food processor, process onions until finely chopped. Add 1 cup cheese, mayonnaise, sour cream, and 2 tsp dill weed; process until well blended. Spoon mixture into 2 9" glass pie plates. Sprinkle tops evenly with remaining 1/2 cup cheese and remaining 1/2 tsp dill weed. Bake 40 to 45 minutes or until lightly browned. Store in airtight container in refrigerator. Give with serving instructions. To serve: Serve with chips or crackers at room temperature or reheat in microwave at 80% for about 3 minutes.