Cook Pasta as directed on box, until al dente. Strain out hot water, refill with cold water to cool pasta, repeat once more to ensure pasta is cooled. Set aside in large tupperware bowl, and place in fridge. Large bowl will allow you to mix in everything else later.
Prepare sauce in small-medium bowl. Mix mayo, sour cream, lemon pepper, lemon juice, dill, and onion. Stir together, and place in fridge to chill and distribute flavors.
Wash grape tomatoes, and cut in halves. Also microwave peas with 2 Tbsp. water for 2min. Strain water out of peas. Take macaroni bowl from fridge and add the tomatoes and peas.
Open salmon cans, and drain water. Add the salmon into large bowl with mac etc.
Take out sauce bowl from fridge and stir into large bowl with macaroni etc. Mix until everything is coated. Return to fridge to chill until time to serve. I like to add a little more lemon pepper after serving as a final touch! Enjoy