1. In a medium bowl, beat cream cheese, sour cream, Parmesan cheese, green onion, and Italian seasoning with an electric mixer on low speed until fluffy. Cover and chill at least 1 hour.
2. If the dip is too thick after chilling, stir in 1 to 2 tablespoons milk. Spoon the dip into serving bowl. If desired, garnish with sliced green onion. Serve with cut-up vegetables, crackers, and or chips. Makes about 30 (1-tablespoon) servings.
3. Make-ahead directions: Prepare dip as above through Step 1. Cover and chill for up to 24 hours. Cut up vegetable dippers and place in resealable plastic bags; chill for up to 24 hours.
4. Creamy Dill Dip: Prepare as above, except omit Parmesan cheese, Italian seasoning, and sliced green onion garnish. Stir 2 tablespoons snipped fresh dill or 2 teaspoons dried dillweed; and 1/2 teaspoon seasoned salt or salt into to the beaten cream cheese mixture. If desired, garnish dip with a dill sprig.