Fill a large pot with water and bring it to a boil. Add the peeled and diced sweet potatoes along with 1 teaspoon of salt. Cook the sweet potatoes until they are tender and easily pierced with a fork, about 15-20 minutes.

Drain the cooked sweet potatoes well and return them to the pot. Immediately add the remaining 1 teaspoon of salt, the minced garlic, cubed butter, and a good amount of freshly ground black pepper. Let the butter melt slightly from the heat of the potatoes.

Using a potato masher, mash the seasoned sweet potatoes to your desired level of smoothness. Alternatively, you can use an electric hand mixer on low speed for a creamier consistency. I like to use a bit of both methods: mash first, then finish with the mixer for extra smoothness.

Add the sour cream to the mashed sweet potatoes and mix thoroughly until incorporated. Transfer the potatoes to a serving bowl.

Garnish the sweet potatoes with chopped fresh parsley and, if desired, an extra pat of butter before serving. For a fresher flavor, I always go for freshly chopped parsley.