Bring a large pot of water to a boil before salting and cooking the pasta until al dente.
While the macaroni cooks, add the sauce ingredients to a food processor or blender. Blend until smooth and set aside.
Add the carrots, onion, and vinegar to a large bowl.
Once the pasta is cooked, strain the water and add to the bowl with the veggies and vinegar. Toss everything together.
Add the cottage cheese sauce and gently fold everything together. Salt and pepper to taste and add any chives or scallions, if desired.
Cover the assembled macaroni salad with cling film and refrigerate for at least 3-4 hours before serving.
