In a large pot, combine the diced potatoes and chicken broth. Bring to a boil, then reduce heat and simmer until potatoes are tender, about 10-12 minutes.

While potatoes are cooking, melt butter in a separate small saucepan. Whisk in flour and cook for 1 minute, creating a roux.

Gradually whisk in milk and heavy cream into the roux until smooth and thickened.

Once potatoes are tender, mash them slightly in the pot using a potato masher or fork, leaving some chunks for texture.

Pour the cream mixture into the pot with the potatoes. Stir well and season with salt and pepper to taste. Heat through for a few minutes, but do not boil.