Egg-Free Amish Pasta Salad

Bring a large pot of salted water to a boil. Add shell pasta and cook, stirring occasionally, until tender yet firm to the bite, about 9 minutes. Drain and set aside to cool.

Stir peas, celery, and green onions together in a large bowl. Whisk mayonnaise, mustard, sugar, vinegar, celery seed, salt, and pepper together in a separate bowl, until sugar dissolves. Pour over vegetables and stir in cooled pasta until thoroughly coated with dressing.

Cover and refrigerate at least 2 hours before serving.