Cook the macaroni until soft. Drain the pasta well. Let it cool fully.
Prepare the veggies
Chop the bell peppers, celery, and onion into small pieces.
Make the dressing
Mix mayonnaise, sour cream, salt, and pepper in a bowl.
Add pasta and cheese
Add the cooked pasta and cheddar cheese to the dressing bowl.
Mix in the veggies
Add the chopped veggies. Stir everything gently.
Chill the salad
Place the salad in the fridge. Let it chill for one hour.
Notes
Use cold pasta for best texture. Cut veggies into tiny pieces. Add more cheese for extra flavor. Chill the salad before serving. Use fresh veggies for a crisp taste.