Peel and dice the potatoes into small squares. Place into a strainer and the place the strainer over a bowl. Cover the potatoes with water and let them sit for a minute. Lift the strainer up and rinse the potatoes one more time. At this point the water should be running clear.
Add to a pot and cover with new water. Bring to a boil and cook until al dente, meaning you can pierce the potatoes with a fork, just soft. Drain the water and pour the potatoes back into the pot to leave the potatoes to dry, about 10 minutes.
Add the potatoes to a big mixing bowl. Add the peas, carrots, relish, capers and mayo. Mix around until everything is coated. Adjust relish, capers and mayo to your liking. Enjoy!