In a large pot, bring water to a boil. Add the potatoes and carrots. Cook until tender, about 15-20 minutes.
Remove the vegetables from the pot, let them cool, then peel and dice them into small cubes.
While the potatoes and carrots are cooking, cook the frozen peas according to package instructions. Drain and let cool.
In a large bowl, combine the diced potatoes, carrots, cooked peas, diced chicken or ham, pickles, and chopped onion.
In a separate bowl, mix together the mayonnaise and sour cream. Season with salt and black pepper to taste.
Add the dressing to the salad mixture and gently toss to combine all the ingredients.
Cover the bowl with plastic wrap and refrigerate for at least 1-2 hours to let the flavors meld.
Garnish with fresh dill if desired before serving.
Enjoy your meal!