Bring a large pot of water to a boil; add salt. Add macaroni; cook until al dente. Drain. Rinse with cold water, and drain. Transfer to a large bowl. Cover with plastic wrap; refrigerate until cool.
Thaw peas under cold running water. Drain. Toss with celery, scallions, and ham in a bowl. Add to macaroni; toss.
Whisk mayonnaise, sour cream, vinegar, sugar, nutmeg, and 1/4 teaspoon salt; fold into macaroni mixture. Season with salt and pepper. Salad can be refrigerated in an airtight container, up to 3 hours.
I made this on the weekend for our weekly family picnic and it was great! I used calorie-wise mayonaise, fat-free sour cream, canned drained sweet peas and I omitted the ham. It was really yummy and my 4-year old daughter especially loved it. Next time I think I'll add tuna in place of the ham suggested.
I have made this for several parties and it is always a hit.
This is one of my favourite lunch salads to make. It is so super easy, it can be made in no time at all, and it makes a lot of salad. The flavours are just great together. When I first read the recipe I thought the nutmeg was an odd choice, but after making it, I realize it was the perfect thing to use!