Bring a large stock pot of water to a boil and add a heavy pinch of salt to the water (to add flavor to macaroni). Once the water is boiling, gently pour in the elbow macaroni. 

Reduce the heat to medium and boil the pasta for about 10 minutes, or until the macaroni is al dente (soft but not mushy). 

While the pasta is boiling, use a grater to grate your onion and your carrots. Alternatively, you can use a very sharp knife to finely mince the onions and carrots. Set the shredded onions and carrots aside.

Once the pasta is done boiling, drain the water and place the hot pasta in a large bowl. While it is still hot, pour the apple cider vinegar directly into the pasta and use a spoon to mix it around so that the vinegar is fully absorbed. 

Now mix in the shredded onion and carrots into the pasta. Then add in the mayonnaise and pepper; add the salt to your taste. Stir everything together until fully combined. Cover and refrigerate for at least one hour, or overnight for the best results. 

And enjoy!