Add pasta, 1 tspn. parsley flakes, dried onion (vary amount depending on how much you like onions), sea salt and pepper to a pot of water large enough to cook and stir all ingredients. Bring to a boil and then cook 8 minutes (al dente') or 10 minutes (soft). Drain in colander and rinse with cold water to chill down the pasta. It is not necessary to remove onion/parsley bits. Return to pot after thoroughly drained. Drizzle with EVOO and stir to coat all pasta, then place pot in refrigerator until completely cooled. To quicken the process place in freezer but keep an eye on it to make sure it's not freezing.
Drain tuna, place in a small bowl and mash with a fork until it's of uniform consistency. Add a small amount of EVOO, remaining parsley flakes, minced onion to taste, salt & pepper to taste. Blend well. When pasta has completely cooled, add tuna mixture, carrot and tomato to pot and blend well. Taste and add EVOO/seasonings as desired.