Cut potatoes into 3/8-inch cubes.

Place the potato cubes in a bowl and add enough water to cover the potatoes. Soak for 5 minutes.

Melt the butter in a large pot over medium heat.

When the butter has melted, add the all-purpose flour. Cook on medium heat for about 1 minute. The mixture should become fragrant and smell like pie dough.

Add the chicken stock and heavy cream. Stir until the soup thickens.

Drain the potatoes and add them to the pot.

Season with salt and ground white pepper.

Cook until the potatoes are fork tender, about 30 minutes.