In a large mixing bowl, make the ranch dressing by combining the ranch seasoning mix, greek yogurt and milk. Whisk to combine. Place the mixing bowl in the fridge while you make the rest of the pasta salad.

Cook the elbow macaroni in salted boiling water according to package instructions. Drain and add to the large mixing bowl with the ranch dressing while the pasta is still warm. Add in the carrots, celery, onion and frozen peas. Toss to combine. It will look a little too saucy at first, but the warm noodles will absorb some of the dressing. Refrigerate for at least 2 hours until it is cooled. After it has cooled, toss it a few more times to evenly distribute the dressing. If needed, add in a little more greek yogurt and milk if the noodles absorbed too much of the dressing.

Serve cold or at room temperature. Will keep refrigerated in an airtight container for 1 week.