The Best Macaroni Salad with Tuna

0 Cook the shell pasta based according to the package directions.
1 Drain the pasta.
2 In a medium bowl add the mayo, Dijon mustard, cheddar cheese, diced sweet pickles, drained tuna, finely diced red onions, salt, and black pepper. 
3 Mix them well.
4 Add the drained pasta and mix them gently.
5 Refrigerate for at least two hours before enjoying.