First, combine the cornstarch with the chicken broth. Dissolve the cornstarch in the broth.
Next, pour the frozen hash browns into the crockpot. Dice the onion the add in with the hash browns.
Now, stir the cornstarch and broth if the cornstarch has settled to the bottom and pour it into the crockpot. Place the crockpot on high for 3 hours or low for 6-7 hours. You'll want to stir the frozen potatoes about halfway through for even cooking.
When the potatoes are soft, use a potato masher and mash some of the potatoes into the soup. This step is optional.
Now, add in the heavy cream and season to taste with salt and black pepper.
Lastly, serve with a garnish of cheese and/or bacon for a classic potato soup finish.