Gather all your equipment: a slow cooker, a sharp knife, a cutting board, and a potato masher or immersion blender. Prepare your workspace for easy assembly.
Wash and peel the potatoes, then cut them into roughly 1-inch cubes. The even size helps them cook uniformly and makes mashing easier later.
Dice the yellow onion finely, which will soften quickly and add a sweet, mellow base flavor to the soup.
Add the cubed potatoes, diced onion, minced garlic, and chicken broth to the slow cooker. Cover with the lid, set to low, and cook for 6 to 8 hours until the potatoes are fork-tender and smell rich and garlicky.
Once the cooking time is up and the potatoes are soft, use a potato masher or immersion blender to mash or blend the soup to your desired texture—chunky or smooth. This helps develop that velvety consistency.
Stir in the heavy cream and add a tablespoon of butter, then season with salt, pepper, and thyme to taste. Mix well and let the flavors meld for a few minutes on warm or low heat.
Check the soup’s consistency. If it’s too thick, stir in a splash of warm broth or water to loosen it. Taste and adjust seasonings as needed for a balanced flavor.
Ladle the hot, creamy soup into bowls, garnish with fresh herbs or bacon if desired, and serve with crusty bread for a perfect cozy meal.
