In a large pot, add 4 cups of frozen hash browns, 1 cup of diced onion, 1 teaspoon of garlic powder, ½ teaspoon of black pepper, 1 teaspoon of salt, 1 teaspoon of dried thyme, and enough water or broth to cover everything by about an inch. Stir gently to mix the ingredients, ensuring they're evenly distributed.

Place the pot over medium-high heat and bring to a rolling boil. Once bubbling, reduce the heat to low, cover the pot, and let it simmer for 30-35 minutes, stirring occasionally until the potatoes are tender and the flavors meld beautifully.

After the potatoes have softened, carefully stir in ¾ cup of heavy cream. Return the pot to low heat and cook for an additional 5 minutes, allowing the soup to thicken slightly.

Ladle the hot soup into bowls, and if desired, sprinkle with ¼ cup of shredded cheese for a delightful, melty finish.