American-Italian Pasta Salad

Bring a large pot of lightly salted water to a boil. Cook fusilli in the boiling water, stirring occasionally, until tender yet firm to the bite, 10 to 13 minutes. Drain, rinse under cold water, and drain again. Transfer to a large bowl.

Meanwhile, whisk mayonnaise, sour cream, milk, and Italian dressing mix together in a medium bowl until smooth. Refrigerate ½ cup dressing until ready to serve; set aside remaining dressing.

Add thawed peas, salami, green onions, celery, olives, and parsley to pasta; stir in remaining dressing until well combined. Cover and refrigerate 8 hours to overnight.