Peel and cut the potatoes into evenly sized pieces.

In a medium pot, bring 8 cups of water to a boil. Ensure the water is enough to cover the potatoes.

Add salt, finely chopped onion, and 2 tablespoons of butter to the boiling water.

Add the cut potatoes to the pot.

Boil until the potatoes are cooked soft and easily pierced with a fork, approximately 15-20 minutes.

Drain the potatoes, retaining 1/4 cup of the cooking water.

In a mid-sized mixing bowl, combine the drained potatoes, reserved 1/4 cup potato water, crushed dried thyme, and 1/2 cup of butter.

Mix together using a cake mixer or electric egg beater until the mixture is soft and creamy. Add more water as needed to achieve a texture suitable for scooping.

Scoop the mashed potatoes into balls using an ice cream scooper.

Place the potato balls in an oblong baking dish.

Melt the remaining butter and baste the potato balls generously.

Bake in a preheated oven at 375°F (190°C) for 15 minutes, or until the tops of the potato balls are golden brownish.