Cook and drain macaroni, saving 1 cup pasta water. Cool macaroni. Rinse in cold water to cool and drain well.
In large bowl, combine yogurt, mayonnaise, onion and seasonings. Add macaroni, toss to coat. Add celery, peas, cucumber and cheese. Mix well. Cover. Chill at least 2 hours or overnight. Pasta has a tendency to absorb a lot of liquid as it sits, so if the salad appears dry, add some of the pasta water to hydrate again.