Peel and dice the potatoes in cubes and add to a pot or saucepan.
Add enough water to cover the potatoes, add enough salt and bring the mixture to a boil.
Cover the pot or pan with lid, simmer in medium low heat for about 25 to 30 minutes until the potatoes are cooked and soft in texture.
If you are cooking potatoes in instant pot pressure cooker, it is not necessary to dice the potatoes early, as it is super easy to boil whole potatoes in instant pot.
Once the potatoes are cooked, let the potatoes cool down.
Once it is cooled enough, save about 1 cup of leftover water and discard the remaining water used for cooking potatoes.
Using a masher, mash the potatoes a bit (do not do a lot of mashing like you do for making mashed potatoes since having little pieces of potatoes is good for the texture of the soup).
Add milk, heavy cream, dried minced onions and garlic powder, stir well to combine with potatoes.
Add butter also to the potatoes, simmer the contents in medium heat until the mixture is boiled and then continue to cook for another 2 to 3 minutes until preferred consistency for the soup is reached.
Keep in mind that the soup will further thicken as it cools down so if you may add little more liquid (water, milk or broth) if necessary.
Finally, add black pepper powder and dried parsley leaves (if using), stir well and serve hot for best results!
You may also add some caramelized onions to the potato soup for even more flavor if you like!